Since the 1980s, there have been thousands of scientific papers on brain SPECT imaging for evaluating many psychiatric and neurological disorders. The Amen Clinics' research library contains our own scientific research along with abstracts of thousands of studies from the U.S. and around the world.



# Patients Author Date Type Notes
10 receiving citalopram Stein 2002 HMPAO Citalopram led to significantly reduced activity in inferior-posterior and other frontal regions. Data are to some extent consistent with work suggesting that trichotillomania, like OCD, is mediated by corticostriatal circuits.
15 receiving citalopram Van der Linden 2000 HMPAO Before and after an eight-week trial of citalopram. Pharmacotherapy led to significantly reduced activity in the anterior and lateral part of the left temporal cortex; the anterior, lateral and posterior part of the left mid frontal cortex; and the left cingulum.
10 ADHD receiving methylphenidate (MPH) treatment Akay 2006 HMPAO Treatment effects of chronic MPH treatment may persist long after the discontinuation of the treatment.
36 Szobot 2003 ECD-SPECT Analysis showed a significant reduction in rCBF in the left parietal region in the MPH group compared with the placebo group.
6 ADHD receiving methylphenidate (MPH) treatment Vles 2003 SPECT Three months after initiation of treatment with MPH we found a down-regulation of the post-synaptic dopamine receptor with a maximum of 20% and a down-regulation of the dopamine transporter with a maximum of 74.7% in the striatal system.
22 ADHD receiving methylphenidate (MPH) treatment/7 normals Langleben 2002 HMPAO Findings suggest that MPH treatment modulates motor and anterior cingulate cortical activity directly or indirectly.
32 ADHD receiving methylphenidate (MPH) treatment Kim 2001 HMPAO Left and right prefrontal areas and caudate and thalamic areas showed significant increases in rCBF after MPH treatment.
7 Rauch 2000 SPECT and 123I-altropane The DAT site was elevated approximately 70% in subjects with ADHD as compared to healthy controls.
10 ADHD receiving methylphenidate (MPH) treatment Krause 2000 trODAT-1 SPECT After MPH specific binding decreased in all patients. Thus, for the first time it could be demonstrated using SPECT that MPH lowers increased striatal DAT availability in adults suffering from ADHD.
Brain Injury
1 receiving valproate Barkai 2004 SPECT with and without acetazolamide injection Valproate treatment was associated with increased prefrontal perfusion concomitant with clinical improvement and abolished response to acetazolamide challenge.
4 receiving zolpidem Clauss 2004 HMPAO Observations point to a GABA based phenomenon that occurs in brain injury and diaschisis that is reversible by zolpidem.
320 receiving hyperbaric oxygen (HBO) therapy Shi 2003 ECD-SPECT HBO therapy has specific curative effects on patients with postbrain injury neural status, and ECD-SPECT could play an important role in diagnosing postbrain injury neural status and monitoring the therapeutic effects of HBO.
5 Laatsch 1999 HMPAO Results suggest that, even in individuals who are more than 2 years post-brain damage, relative increases in rCBF can be demonstrated following individualized CRT and that most of these changes can be related to improvements on neuropsychological tests.
Cerebral Vascular Disease
77 receiving acetazolamide/24 normals Hori 2002 ECD-SPECT In patients with cerebrovascular disease, the reduction of the mean IR and regional IR was parallel with the degree of stenosis.
1 receiving methylphenidate (MPH) treatment Watanabe 1995 SPECT A patient with prominent apathy secondary to multiple subcortical infarcts was treated successfully with MPH. SPECT and reaction time testing showed selective improvement of frontal system function, consistent with a recent model of frontal-subcortical circuits and behavior.
10 receiving acetyl-L-carnitine Postiglione 1990 Xe-SPECT It is concluded that acetyl-L-carnitine at a dosage of 1.5 g i.v. improves cerebral blood flow in patients with cerebrovascular disease.
51 AD receiving donepezil Shimizu 2006 SPECT Study suggests that the diversity of clinical responses to donepezil therapy in AD patients is associated with rCBF changes, mainly in the frontal lobe.
19 PD with dementia after 6 months acetylcholinesterase inhibitors (ChEIs) treatment Ceravolo 2006 ECD-SPECT Data confirm the efficacy of ChEIs in the treatment of PD with dementia mainly on attention and executive functions, and the functional findings indicate that this cognitive improvement could be associated with a sort of pharmacological frontal “re-afferentation”.
26 PD with depression, half receiving fluoxetine Fregni 2006 SPECT/repetitive transcranial magnetic stimulation (rTMS) Depression in patients with PD is correlated with a dysfunction of the frontal-limbic network that can be modulated by two different antidepressant therapies.
271 PD receiving Levodopa/90 PD receiving placebo Fahn 2005 SPECT Outcomes not only indicate that Levodopa is effective in a dose-dependent manner in overcoming the signs and symptoms of PD, they also support the concept that the drug does not hasten the disease progression, but rather may slow down the rate of the disease.
15 PD receiving Levodopa Schillaci 2005 123I-FP-CIT-SPECT Scanned while on medication and after a 20 day wash-out. Study suggests that levodopa does not affect brain imaging and confirm that it is not necessary to withdraw this medication to measure DAT levels with SPECT.
1 PD receiving Levodopa Taguchi 2004 ECD-SPECT Findings suggest that L-dopa may directly activate the metabolism in the bilateral corpus striatum, and that rCBF in the corpus striatum may be increased indirectly according to the increase of movement in the legs. It is also suggested that denervation super sensitivity to dopamine may exist in the corpus striatum on the contralateral side of the signs and symptoms in this patient.
24 AD receiving ChE inhibitors (donepezil, rivastigmine) Ceravolo 2004 ECD-SPECT/CT Data suggest that cognitive or behavioral benefits after ChE inhibitor therapy are related to a clear increase of rCBF in crucial areas specifically involved in the attentional and limbic networks.
25 PD receiving alpha-dihydroergocryptine (DEC) or Levodopa Popperl 2004 123I-IPT-SPECT Results of this pilot study suggest that as compared to Levodopa monotherapy. DEC may have beneficial effects on decline of dopamine transporter binding similar to those recently described for pramipexole.
36 PD receiving Levodopa Contin 2004 123I-FP-CIT SPECT Study did not identify clinically relevant in vivo DAT neurochemical function phenotypes or Levodopa response patterns associated with the DAT polymorphism.
1 frontotemporal dementia receiving methylphenidate (MPH) treatment Goforth 2004 SPECT/EEG EEG correlated with SPECT, and demonstrated profound left greater than right bi-frontotemporal slowing, which normalized partially after MPH administration. The patient has remained on MPH as an outpatient, and has had significant behavioral improvement.
16 AD after 1 year of donepezil therapy Rodriguez 2004 HMPAO/EEG The posterior parietal region is often affected by hypoperfusion in AD, as a likely consequence of disconnection from the atrophic mesial temporal cortex. Metabolic activation induced by AChEIs may especially influence this area, which could be one of the pathophysiological substrates of the cognitive effects of AChEIs.
12 AD receiving donepezil or placebo Kemp 2003 123I-QNB SPECT Both placebo and actively treated groups had reductions in QNB uptake. Greater reductions in receptor binding were demonstrated in the placebo group than in those receiving active treatment. Cholinergic treatment may play a neuroprotective role.
61 Hanyu 2003 SPECT Results suggest that frontal function, as assessed by SPECT, affects the patient’s response to treatment with donepezil. Measuring rCBF may aid in the selection of possible treatment responders.
41 AD or VaD receiving cholinesterase inhibitors (ChE-I) Lojkowska 2003 SPECT Increased levels of acetylcholine in the brain after ChE-I treatment may support the cholinergic regulation of rCBF, and in result increase it. Such effects seem to be more pronounced in the more affected brain regions.
10 PD receiving repetitive frontal transcranial magnetic stimulation (rTMS)/6 PD receiving occipital rTMS Ikeguchi 2003 ECD-SPECT Because there were no significant relations between improved clinical tests and reduced rCBF, we speculate that the indirect effects of 0.2 Hz rTMS on subcortical structures are related to improved parkinsonian symptoms.
27 Vennerica 2002 HMPAO Results suggest that alterations in the clinical and cognitive status of patients receiving a cholinesterase inhibitor are paralleled by changes in rCBF.
10 AD receiving milameline Zheng 2002 HMPAO Decreased rCBFs were observed at the temporal cortex on both sides of the brain and at the left parietal cortex on the activation SPECT images after milameline, whereas no statistically significant rCBF change was found on the baseline SPECT images.
25 AD receiving donepezil Nobil 2002 SPECT Brain perfusion is preserved in AD patients undergoing chronic donepezil therapy while it is reduced in untreated patients.
35 receiving donepezil Nakano 2001 ECD-SPECT Treatment with donepezil for 1 y appears to reduce the decline in rCBF, suggesting preservation of functional brain activity.
12 AD receiving donepezil Staff 2000 HMPAO Donepezil improves cognitive and global function in patients with mild to moderate AD. When analyzed in terms of rCBF, we found that the most significant increase in blood flow occurred in the frontal lobes.
30 AD Mega 2000 HMPAO A pre-treatment orbitofrontal syndrome may predict behavioral response to cholinesterase inhibitor therapy in AD.
24 AD receiving linopirdine (LPD)/13 normals van Dyck 1997 ECD-SPECT The parietal activation seen with LPD and other cholinergic AD drug therapies suggests the importance of measuring parietal lobe neuropsychological function in the course of evaluating these drugs.
10 Agnoli 1992 HMPAO Deprenyl improved cognitve efficiency and no change in rCBF. Placebo showed no cognitive change and worsening of rCBF
23 receiving transcranial magnetic stimulation (TMS) Fujita 2005 ECD-SPECT Results suggest that although repetitive TMS is steadily becoming the mainstay technique today, single-pulse TMS also possesses sufficient anti-depressive effects.
16 depressed/12 normals Argyelan 2005 trODAT-1 SPECT In good agreement with other PET studies, we found 20.84% DAT occupancy during bupropion treatment. The lack of correlation between the efficacy of therapy and occupancy of DAT may raise the question as to whether other mechanisms are involved in the effect of bupropion.
23 receiving fluoxetine/10 receiving paroxetine Kugaya 2004 123I-CIT-SPECT Higher pre-treatment availability and greater occupancy of SERT in diencephalon may predict better treatment course in response to SSRIs.
14 who were electroconvulsive therapy (ECT) remitters/22 who were pharmacological treatment remitters/25 normals Navarro 2004 HMPAO Result suggests that elderly patients given ECT for severe unipolar major depression do not suffer brain perfusion abnormalities at long-term follow-up. Study adds new evidence in favor of the safety of the ECT, particularly in elderly subjects.
7 Davies 2003 HMPAO Data confirm limbic cortical rCBF changes associated with effective antidepressant treatment.
15 receiving electroconvulsive therapy (ECT) Vangu 2003 HMPAO Improvement in frontal and temporal hypoperfusion was seen only in those patients who responded to ECT. Cerebral hypoperfusion may be a state-dependent marker in depressive illness.
7 receiving venlafaxine Davies 2003 HMPAO Data confirm limbic cortical rCBF changes associated with effective antidepressant treatment.
17 receiving repetitive transcranial magnetic stimulation (rTMS) Mottaghy 2002 SPECT Prior to rTMS there was a significant left-right asymmetry favoring the right, whereas 2 weeks after the rTMS treatment this asymmetry was reversed. The rCBF in limbic structures was negatively correlated with the outcome and rCBF in several neocortical areas was positively correlated.
9 receiving electroconvulsive therapy (ECT) Awata 2002 HMPAO After ECT there was increased activity compared to baseline.
10 Elizagarate 2001 HMPAO All patients had a relative increased perfusion of the temporal lobes and basal ganglia. Other changes from the basal study were areas of decreased perfusion of the occipital lobe and parietal lobe.
7 treatment resistant patients receiving repetitive transcranial magnetic stimulation (rTMS) Catafau 2001 HMPAO A significant rCBF increase after the 10 sessions of rTMS was found in the left prefrontal region.
20 drug resistant receiving electroconvulsive therapy (ECT) Mervaala 2001 ECD-SPECT/IMZ-SPECT Increased perfusion after ECT was observed in right temporal and bilateral parietal cortices, whereas no reductions in relative ECD uptake were seen after ECT. IMZ revealed a significant increase in the benzodiazepine receptor uptake in all studied cortical regions except temporal cortices.
23 receiving transcranial magnetic stimulation (TMS) Nahas 2001 ECD-SPECT Repeated daily TMS over the prefrontal cortex in medication-free depressed adults appears to change both local and remote blood flow in a manner that may also depend on the frequency of stimulation and coil to outer cortex distance.
28 receiving venlafaxine hydrochloride and interpersonal psychotherapy (IPT) Martin 2001 HMPAO/MRI This preliminary investigation has shown limbic blood flow increase with IPT yet not venlafaxine, while both treatments demonstrated increased basal ganglia blood flow.
9 receiving electroconvulsive therapy (ECT) Escobar 2000 SPECT Pre- vs. post-ECT comparisons showed significant reduction of catatonic symptoms in both groups. Patients with mood disorders needed less ECT sessions and showed greater clinical improvement.
20 receiving nortriptyline or sertraline /20 normals Nobler 2000 Xe-SPECT The depressed sample had reduced rCBF in frontal cortical regions when compared with control subjects.
14 Holthoff 1999 HMPAO Before sleep deprivation the responding patients had a significantly higher anterior cingulate perfusion than the non-responding patients, which normalized after sleep deprivation.
15 receiving a selective serotonin re-uptake inhibitor (SSRI) Klimke 1999 123I-IBZM SPECT In the depressive group there was a significant linear correlation between treatment response and change of D2 receptor binding during treatment in the basal ganglia. Results suggest an association between changes in the dopaminergic system and treatment response in major depression.
1 receiving fluoxetine Tauscher 1999 Beta-CIT SPECT Four hours after injection of the tracer more than 40% of serotonin transporters were blocked.
9 Kocmur 1998 Bicisate SPECT Findings implicate dysfunction of the frontal and temporal cortex in clinically depressed patients before specific drug treatment. Clinical improvement and decreases in HAMD score after 3 weeks and after 6 months reflect the treatment effect on mood-related rCBF changes.
10 Vasile 1997 HMPAO Relative increases in rCBF were observed in all brain regions compared to cerebellum in treatment responders, whereas non-responders showed no change or decreases in rCBF relative to cerebellum. Significant differences in mean percentage change in rCBF between responders and non-responders were detected in frontal and cingulate cortex, and thalamus.
20 Bonne 1996 HMPAO Findings imply that reduced rCBF in depression, as reflected in HMPAO uptake, is a “state”-related property and is reversible by successful treatment. HMPAO uptake may serve as an objective state marker for depression, an indicator of the severity of depression and as an objective means of evaluating response to treatment.
20 Ebert 1994 HMPAO It is possible that limbic overactivation may characterize depressed responders to total sleep deprivation as a distinct subtype. Another possibility is that the pattern of limbic hyperactivation reflects the increased number of bipolar patients in the responder group, with response to total sleep deprivation being only a covariate of this bipolar-unipolar distinction.
15 receiving electroconvulsive therapy (ECT) Scott 1994 HMPAO Significant decreases in tracer uptake were confined to the inferior anterior cingulate cortex. The changes were correlated with the severity of depressive symptoms and more weakly with decrements of memory function produced by ECT.
28 Goodwin 1993 HMPAO Before sleep deprivation the responding patients had a significantly higher anterior cingulate perfusion than the non-responding patients, which normalized after sleep deprivation.
Drug Abuse
36 heroine dependent taking U’finer capsules Jia 2005 trODAT-1 SPECT Findings suggest that U’finer is a reliable herbal medicine in the treatment of heroin dependency.
49 cocaine dependent/18 normals all receiving either asprin, amiloride, or placebo Kosten 2003 HMPAO Following treatment, areas of hypoperfusion were improved with amiloride, unchanged with aspirin, and worsened with placebo in comparison to baseline levels.
9 cocaine dependent receiving isradipine Gottschalk 2002 HMPAO When comparing the scan before isradipine to that after using SPM analysis, the ratio of hypo- to hyper-fusion showed a 16% increase in the maximum Z scores and 30% fewer areas of hypo-perfusion among those cocaine abusers with deficits.
16 alcohol dependent receiving naltrexone Catafau 1999 HMPAO The rCBF decrease detected by SPECT after naltrexone challenge in structures rich in opioid receptors, such as the basal ganglia and the left mesial temporal region, may reflect a naltrexone-induced decreased metabolic activity in these areas.
15 cocaine and heroin dependent receiving buprenorphine and/or placebo Levin 1996 HMPAO Buprenorphine treatment, and not abstinence from drug use alone, leads to improvement in regional cerebral perfusion abnormalities in chronic cocaine- and heroin-dependent men.
11 opiate dependent receiving buprenorphine for 7 days, then naltrexone/placebo van Dyck 1994 HMPAO Naltrexone produced significantly greater signs and symptoms of opiate withdrawal than placebo. Analysis of variance revealed no significant regionally specific effect of naltrexone on rCBF ratios. Severity of withdrawal, however, showed a significant negative correlation with rCBF in the anterior cingulate cortex following naltrexone.
30 receiving lamotrigine Joo 2006 ECD-SPECT Lamotrigine medication was found to reduce perfusion in cortico-thalamo-limbic areas, the orbitofrontal cortex, and brainstem.
1 temporal lobe epilepsy receiving risperidone Oner 2005 SPECT/MRI After risperidone treatment, symptoms remitted. SPECT indicated that the left temporal hypoperfusion was normalized. After discontinuation of risperidone, symptoms returned, and electroencephalography revealed generalized slow-wave activity particularly prominent in the left temporal region.
23 receiving vagal nerve stimulation (VNS) Van Laere 2002 ECD-SPECT In the acute, initial setting, the left thalamus, right parahippocampal gyrus, and right hippocampus were deactivated by VNS. Perfusion changes in chronic VNS correlated negatively with the pre-stimulus perfusion pattern, indicating the tendency toward decreased brain activity on VNS.
7 receiving vagal nerve stimulation (VNS) Ring 2000 HMPAO/EEG Results support the hypothesis that VNS may exert an antiepileptic action by an effect on thalamic activity.
12 receiving vagal nerve stimulation (VNS) Van Laere 2000 ECD-SPECT Our findings are consistent with the hypothesis that acute VNS reduces seizure onset or propagation through inhibition of the thalamic relay center.
Normal Aging
48 receiving Ginkgo Biloba or placebo Santos 2003 SPECT Although the mechanisms by which Ginkgo biloba may contribute to overall enhancement of the parameters evaluated have not been specified, this plant extract certainly appears to be effective in the treatment of cognitive deficits in older people.
30 receiving combination of pentifylline and nicotinic acid Dormehl 1999 HMPAO Results indicated a statistically significant improvement in CBF of the total brain, with a more pronounced improvement in the cerebellum and frontal regions, where a definite shift from abnormal to normal blood flow was detected.
1 receiving carbamazepine Staedt 1995 123I-IMZ SPECT/EEG After 2 months of treatment the patient was symptom-free, and a normal BZ receptor density and no pathological EEG signs were found.
10 after 1 year of citalopram Stengler-Wenzke 2006 123I-CIT-SPECT Higher occupancy of serotonin transporter by citalopram seems to be associated with better clinical response after 1 year of SSRI treatment of patients with OCD.
22 receiving fluvoxamine Ho Pian 2005 HMPAO Pre-treatment cerebellar and whole brain HMPAO uptake was significantly higher in responders to treatment compared with non-responders. We suggest that the thalamus plays a central role in the response to drug treatment.
14 receiving inositol Carey 2004 HMPAO Data may support the idea that inositol effects a clinical response through alternate neuronal circuitry to the SSRIs and may complement animal work, proposing an overlapping but distinct mechanism of action.
18 receiving paroxetine/12 normals Diler 2004 HMPAO The right and left caudates, right and left dorsolateral prefrontals, and cingulate had significantly higher rCBF in children with OCD than in the controls. These areas, in addition to the right anteromedial temporal, showed significant rCBF reduction after treatment with paroxetine.
9 receiving sertraline/7 receiving desipramine Hoehn-Saric 2001 HMPAO After 12 weeks of treatment, responders showed a diffuse reduction of rCBF in prefrontal regions while non-responders showed only a few scattered low-frequency responses. Thus, higher prefrontal and subcortical activity was associated with better response to drug treatment.
14 receiving sumatriptan and placebo Stein 1999 HMPAO It may be hypothesized that increased frontal activity in some patients with OCD is itself a compensatory mechanism. In patients with such compensatory hyperactivity, administration of a serotonin auto-receptor agonist results in decreased frontal activity and exacerbation of OCD symptoms.
1 receiving fluoxetine Hoehn-Saric 1991 HMPAO Authors report the occurrence of apathy, indifference, inattention, and perseveration in an OCD patient taking of fluoxetine. These changes were associated with a decrease in cerebral blood flow in the frontal lobes and changes in neuropsychological tests generally associated with frontal lobe impairment.
6 receiving fluoxetine Hoehn-Saric 1991 HMPAO Treatment significantly reduced the patients’ hyperfrontality, as determined by the ratio between medial-frontal and whole cerebral cortex blood flow, and significantly lowered ratings of OCD and anxiety symptoms.
6 PTSD receiving eye movement desensitization and reprocessing (EMDR) treatment Lansing 2005 SPECT In our study EMDR was an effective treatment for PTSD, showing both clinical and brain imaging changes.
8 Penades 2002 SPECT After treatment an enhancement in neuropsychological performance was found, especially in executive functions. Although the prefrontal blood flow changes were small and non-specific, they suggest a reduction of the cognitive hypofrontality after neuropsychological treatment.
28 Martin 2001 HMPAO This preliminary investigation has shown limbic blood flow increase with IPT yet not venlafaxine, while both treatments demonstrated increased basal ganglia blood flow.
6 Levin 1999 SPECT Upon recall of the traumatic memory during SPECT scanning, two areas of the brain were hyperactive post-EMDR treatment relative to pretreatment: the anterior cingulate gyrus and the left frontal lobe.
30 receiving risperidone/15 normals Mateos 2006 123I-FP-CIT SPECT First episode schizophrenic patients treated with risperidone have a decrease striatal DAT binding assessed with SPECT. This alteration could be related to the own schizophrenia disease or be secondary to the antipsychotic treatment.
9 receiving antipsychotic treatment Novak 2005 ECD-SPECT/PET Increased blood flow was observed bilaterally in dorsolateral frontal lobes after 10 weeks of antipsychotic medication. Significant amelioration of r-CBF correlated with clinical improvement.
5 drug-free/7 typical antipsychotic treated/9 clozapine treated/13 normals Bressan 2005 123I-CNS-1261-SPECT Clozapine treatment resulted in a global reduction in 123I-CNS-1261 binding to the NMDA receptor intrachannel PCP/MK-801 site in vivo. This supports an effect of the drug on glutamatergic systems that could be exploited for future antipsychotic drug discovery.
20 Hajak 2004 ECD-SPECT/repetitive transcranial magnetic stimulation (rTMS) Beneficial effects of high-frequency rTMS on negative and depressive symptoms were found, together with a trend for worsening positive symptoms in schizophrenic patients.
7 receiving risperidone/9 taking olanzapine Frankle 2004 123I-IBZM-SPECT after 3 weeks of treatment Data indicate that the dosage of these medications reduces DA stimulation of D(2) receptors to levels slightly lower than those found in un-medicated healthy subjects.
10 receiving quetiapine Pavics 2004 123I-IBZM-SPECT D2 receptor occupancy and its changes during quetiapine therapy were related to the prognosis of the treatment efficacy.
27 receiving either olanzapine or haloperidol Paquet 2004 123I-IBZM-SPECT Authors concluded that: 1) striatal D2 receptor blockade may alter procedural learning in humans; and 2) olanzapine may have a protective effect on procedural learning, even at doses that produce striatal D2 receptor occupancy as high as that found with haloperidol.
8 receiving clozapine Raedler 2003 123I-QNB SPECT Preliminary data indicate that reduction of muscarinic receptor availability by clozapine can be measured in vivo and that moderate daily doses are associated with moderate to high reductions of muscarinic receptor availability.
24 receiving haloperidol or olanzapine de Haan 2003 123I-IBZM SPECT Olanzapine may need to be dosed higher than 7.5 mg/day for most patients, and haloperidol needs to be individually titrated in the very low dose range to reach optimal occupancy.
8 Penades 2002 SPECT After treatment an enhancement in neuropsychological performance was found, especially in executive functions. Although the prefrontal blood flow changes were small and non-specific, they suggest a reduction of the cognitive hypofrontality after neuropsychological treatment.
27 Bernardo 2001 123I-IBZM SPECT Olanzapine led to a mean striatal D2 receptor occupancy of 49%, which was significantly lower than that induced by haloperidol. Also, associated with less EPS.
7 receiving olanzapine/12 normals Raedler 2000 123I-IQNB SPECT Data indicate that olanzapine is a potent and subtype-selective muscarinic antagonist in vivo, perhaps explaining its low extrapyramidal side effect profile and low incidence of anticholinergic side effects.
36 receiving olanzapine or risperidone Lavalaye 1999 123I-IBZM SPECT Both olanzapine and risperidone induce high striatal D2 receptor occupancy, dependent on dose and group formation. The lower incidence of prolactin elevation with olanzapine, compared to risperidone, may not be attributed to a lower D2 receptor occupancy.
20 receiving risperidone Dresel 1998 123I-IBZM SPECT Findings suggest an exponential dose-response relationship between the daily dosage of risperidone and the dopamine D2 receptor occupancy. The dose-response curve for risperidone, however, shows greater similarity to that of haloperidol.
24 Erkwoh 1997 HMPAO Before treatment there was only a slight hypofrontality, and hypoperfusion was observed in the left temporal superior region. After treatment, hypofrontality was reduced to one region and temporal hypoperfusion disappeared.
6 receiving risperidone Berman 1996 HMPAO Findings suggest that the improvement in psychotic symptoms after risperidone is associated with a decrease in frontal and temporal activity.
6 receiving haloperidol Jibiki 1992 HMPAO Results indicate that haloperidol affects perfusion patterns in schizophrenics.
Total Patients Total Authors Total Studies
2695 107 107


If you want to speak to someone immediately, you can call a qualified Patient Care Coordinator with Amen Clinics. We can start to answer your questions and help you book a Full Evaluation with Amen Clinics. Call Today! 888-208-0037

Book an evaluation

Have a Question?