Anterior internal capsule volumes increase in patients with schizophrenia switched from typical antipsychotics to olanzapine.

Abnormalities in connectivity are thought to contribute to the symptoms of schizophrenia. Accumulating evidence suggests that antipsychotic medication affects both subcortical and cortical grey and white matter volumes. The goal of this study was to investigate the effects of antipsychotic medication on two white matter tracts: a subcortical-cortical tract, the anterior and posterior limbs of the internal capsule; and a cortical-cortical tract, the corpus callosum. Magnetic resonance imaging was conducted on 10 chronic schizophrenia patients treated with typical antipsychotics and 20 healthy controls at baseline. Patients were switched to olanzapine and both groups were rescanned after 1 year. At baseline, the volume of the anterior limb of the internal capsule was 24% smaller in typical-treated patients than controls (p = 0.009). Patients treated with greater amounts of chlorpromazine-equivalent daily dosage had smaller anterior internal capsule volumes at baseline (r = -0.65, p = 0.04). At follow-up, after being switched to olanzapine, there were no significant differences between patients and controls. Patients with schizophrenia had a significant 25% increase in anterior internal capsule volume from baseline to follow-up compared with controls (p = 0.04). These effects were most prominent in the anterior limb of the internal capsule, which consists of fronto-thalamic pathways, and were not statistically significant in the posterior limb of the internal capsule or corpus callosum. Olanzapine may be effective in normalizing fronto-thalamic structural connectivity in schizophrenia.

Reduced anterior internal capsule and thalamic volumes in first-episode psychosis.

BACKGROUND: The thalamus is the gateway for sensory and motor information en route to the cortex. Information is processed via thalamocortical and corticothalamic pathways coursing through the internal capsules. In this study, we investigated the relationship between the anterior limb of the internal capsule, posterior limb of the internal capsule, and thalamus in first-episode psychosis (FEP). METHODS: Twenty-nine FEP subjects (26 DSM-IV schizophrenia, 2 schizoaffective disorder, 1 psychosis not otherwise specified) and 22 healthy volunteers participated in this study. Anterior limb of the internal capsule (AIC), posterior limb of the internal capsule (PIC), and the thalamus volumes were manually determined from MRI scans. RESULTS: FEP subjects had reduced AIC volumes (F(1,45)=6.18, p=0.017) and thalamic volumes (F(1,45)=8.00, p=0.007) compared to healthy volunteers. PIC volumes did not differ. Significant correlations between AIC volumes and thalamic volumes were observed in subjects with FEP, but not in healthy volunteers. Negative relationships between thalamic volumes and symptom severity were also observed. CONCLUSIONS: The AIC and thalamic volumes were reduced in subjects with FEP compared to healthy volunteers. Abnormalities in thalamocortical and orticothalamic pathways may contribute to functional disruption of neural circuits in psychosis.

An MRI study of basal ganglia volumes in first-episode schizophrenia patients treated with risperidone.

OBJECTIVE: The basal ganglia may contribute to extrapyramidal movement disorders, affective disturbances, and cognitive deficits in schizophrenia. Basal ganglia volumes are putatively affected by antipsychotic medications. The purpose of this study was to determine the long-term effects of risperidone treatment in a cohort of first-episode patients with schizophrenia. METHOD: The subjects were 30 patients with first-episode schizophrenia, 12 patients chronically treated with typical antipsychotics, and 23 healthy comparison subjects. They were scanned by magnetic resonance imaging at baseline. The first-episode patients received 1 year of continuous risperidone treatment, after which they and the comparison subjects were rescanned. Caudate, putamen, and globus pallidus volumes were determined from coronal images. RESULTS: The baseline caudate, putamen, and globus pallidus volumes were significantly larger in the chronically treated patients than in the untreated first-episode subjects and comparison subjects. These volumes did not differ between the first-episode patients and healthy comparison subjects. Basal ganglia volumes were unchanged after 1 year of exposure to risperidone in the first-episode subjects. Extrapyramidal movement disorders were present in the majority of chronically treated patients and more than one-third of the never-medicated first-episode patients at baseline. CONCLUSIONS: This group of first-episode patients did not exhibit abnormalities of basal ganglia volumes, nor were basal ganglia volumes affected by exposure to risperidone. Movement disorders were observed in both first-episode and chronically treated patients, suggesting effects of both illness and medications.

Endovascular treatment of a "blister-like" aneurysm of the internal carotid artery.

BACKGROUND: "Blister-like" aneurysms of the supraclinoid internal carotid artery have recently been recognized as having unique pathological and clinical features. Little is known regarding their optimal treatment modality. METHODS: We report a case of a "blister-like" aneurysm of the internal carotid artery treated with Guglielmi detachable coil (GDC) embolization. CASE REPORT: A 55-year-old man presented with a Hunt & Hess grade II subarachnoid hemorrhage. Computed tomography revealed diffuse subarachnoid blood. Cerebral angiography demonstrated a broad-based bulge on the medial wall of the right distal internal carotid artery. The patient was taken to the operating room and underwent a right pterional craniotomy and wrapping of this unclippable aneurysm. On postoperative day 11, he developed signs of vasospasm, and repeat angiography showed remarkable growth of the aneurysm. The aneurysm was believed to be amenable to endovascular therapy and was treated by GDC embolization. The patient recovered well and remained neurologically intact on follow-up examinations. Repeat cerebral angiography was performed three and nine months following his initial presentation and revealed a significant aneurysm neck remnant. This neck remnant was treated by repeat GDC embolization 13 months following his subarachnoid hemorrhage. CONCLUSIONS: "Blister-like" aneurysms of the internal carotid artery are important to recognize and are difficult to manage using traditional surgical approaches. Early repeated cerebral angiography is indicated and, where appropriate, endovascular therapy should be considered in the management of these patients.

Direct sampling of the cavernous sinus in Cushing's disease.

Sampling of the petrosal sinus is a sensitive and accurate method of diagnosing Cushing's disease. Sampling of the inferior petrosal sinus has been performed with a steam-shaped no. 4 or 5 French soft catheter in some centres. However, a recent report described two patients who suffered major injury to the brain stem as a result such sampling. The authors describe a series of five patients who underwent simultaneous, direct sampling of the cavernous sinuses with a Tracker microcatheter (Target Therapeutics, Fremont, Calif.) for the diagnosis of Cushing's disease. No complications occurred in this small group. The authors conclude that this procedure is a safe and accurate means of diagnosing Cushing's disease; the technique is also helpful in locating adrenocorticotropin-producing microadenoma.