P-wave indices in Japanese patients with ischemic stroke: Implication of atrial myopathy in subtype of ischemic stroke.

BACKGROUND: P-wave indices have been not fully studied in subtypes of ischemic stroke. We compared P-wave indices among embolic stroke, lacunar stroke and the control. METHODS: P-wave duration, advanced interatrial block (aIAB) defined as P-wave duration ≥120 ms and biphasic (positive negative) morphology in inferior leads, and P-terminal force in lead V1 (PTFV1) were measured at the time of the first episode of cardioembolic stroke in 81 patients with paroxysmal atrial fibrillation (PAF), and in 64 patients with lacunar stroke, and compared with 100 control subjects. The latter two groups had no episode of PAF. RESULTS: The age of participants was 76 ± 11 years. Age, sex distribution, body mass index and CHADS2 score were comparable among three groups. Maximum P-wave duration, the longest across 12 leads, was significantly prolonged in cardioembolic and lacuna stroke compared to the control; 118 ± 12 ms and 118 ± 11 ms vs. 110 ± 11 ms, respectively (P < 0.0001). P-wave duration ≥120 ms and aIAB were more prevalent in ischemic stroke groups than the control, and associated with a higher Odds ratio for stroke, more so in cardioembolic stroke. However, PTFV1 value and the prevalence of PTFV1 ≥ 4.0 ms·mV were significantly not different among the three groups. Abnormal P-wave duration and aIAB indicating the presence of atrial myopathy were present in cardioembolic and lacuna stroke. CONCLUSION: Atrial myopathy was present in cardioembolic and lacunar stroke, but it can't be the direct cause of small vessel occlusion in lacunar stroke. Roles of atrial myopathy in each subtype of ischemic stroke should be studied.

[A case of postural and kinetic tremor caused by diffuse axonal injury].

We reported a 25-year-old woman with postural and kinetic tremor caused by diffuse axonal injury. The patient demonstrated consciousness disturbance, left oculomotor palsy and tetraparesis because of an automobile accident. T2-weighted and FLAIR MRI showed features of diffuse axonal injury. Hyperintense lesions appeared in the corpus callosum, fornix, dorsal portion of midbrain, right cerebral peduncle, and bilateral internal capsules. About 3 weeks later, head tremor and left hemiparesis appeared with improvement of consciousness. Administration of trihexyphenidyl decreased the tremor. Ten weeks after the accident, a coarse tremor in the head and right upper extremity developed after withdrawal of trihexyphenidyl. Tremor in the right upper limb predominantly occurred while maintaining an upright posture and with intended movements. Re-administration of trihexyphenidyl decreased the tremors. The dentatothalamic pathway is one of the lesions responsible for posttraumatic tremor. Our patient demonstrated lesions of diffuse axonal injury involving the dentatothalamic pathway. We considered that these lesions were associated with postural and kinetic tremor in our case. The tremor occurred at least 3 weeks after the accident. This finding suggested that the tremor was caused by transsynaptic alternations of thalamus or the extrapyramidal system secondary to involvement of the dentatothalamic pathway.

[A case of idiopathic portal hypertension (IPH) with hypermanganemia presenting as spastic gait].

A 48-year-old women was admitted to our hospital because of gradually developed spastic gait. She showed spasticity of the lower extremities with mild weakness. Laboratory tests disclosed decreased WBC and platelet counts and mild increases of transaminase and total bilirubin. Blood manganese level was markedly increased (6.0 micrograms/dl). Abdominal ultrasound showed splenomegaly, and abdominal angiography showed a dilatation of the portal and paraumbilical veins. T1-weighted MR images showed high signal intensities at the bilateral globus pallidus and cerebral peducles, and T2-weighted images showed high signal intensities at the bilateral deep white matter, posterior limbs of the internal capsule and right upper cervical spinal cord. Following the diagnosis of IPH, splenectomy was performed. The blood level of manganese decreased thereafter and her neurological deficits gradually improved. Hepatic diseases often show high signal intensities at the basal ganglia on T1-weighted images, and this seemed to be due to accumulation of manganese in our case. Because demyelination or axonal injury of the spinal cord are found in hepatic disease, we speculate that the high signal intensities at the spinal cord on T2-weighted images of our case reflect hepatic myelopathy, which may also be caused by high blood levels of manganese.