[A patient with Fisher syndrome and pharyngeal-cervical-brachial variant of Guillain-Barré syndrome having a complication of SIADH].

A 69-year-old woman complained of diplopia and truncal titubation after upper respiratory infection. She presented with mydriasis and external opthalmoplegia of bilateral eyes, ataxia, hyporeflexia and cervical-brachial muscle weakness. The protein abnormally increased (49 mg/dl) in the cerebrospinal fluid, and the serum anti-GQ1b and anti-GT1a IgG antibodies were positive. The blood sodium level was 128 mmol/l indicating hyponatremia. She had low plasma osmolarity (251 mOsm/kg), high urine osmolarity (357 mOsm/kg) and high urine sodium level (129 mmol/l), while the blood level of antidiuretic hormone was not able to be measured. She was diagnosed to have Fisher syndrome (FS), pharyngeal-cervical-brachial variant of Guillain-Barré syndrome (PCB) and syndrome of inappropriate secretion of antidiuretic hormone (SIADH). The hyponatremia improved with hyperosmotic saline infusion and restriction of water intake. Intravenous immunoglobulin therapy (IVIg) was effective only for ataxia, but the other symptoms mostly remained unchanged for a month. The serum anti-GQ1b IgG antibody was still positive even after one month. We performed high-dose intravenous steroid-pulse therapy. Then the mydriasis, external opthalmoplegia and cervical-brachial muscle weakness were immediately improved. This was a rare case of FS and PCB complicated with SIADH. IVIg, not steroid therapy, is generally chosen for FS since FS is considered as a variant of Guillain-Barré syndrome and steroid is not effective for Guillain-Barré syndrome as was proven by double-blind study. We suppose that the combined therapy of IVIg and steroid would be effective in patients with complicated symptoms and multiple antibodies.

Aquaporin-4 expression in distal myopathy with rimmed vacuoles.

BACKGROUND: Distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy is clinically characterized by the early involvement of distal leg muscles. The striking pathological features of the myopathy are muscle fibers with rimmed vacuoles. To date, the role of aquaporin-4 water channel in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy has not been studied. CASE PRESENTATION: Here, we studied the expression of aquaporin-4 in muscle fibers of a patient with distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy. Immunohistochemical and immunofluorescence analyses showed that sarcolemmal aquaporin-4 immunoreactivity was reduced in many muscle fibers of the patient. However, the intensity of aquaporin-4 staining was markedly increased at rimmed vacuoles or its surrounding areas and in some muscle fibers. The fast-twitch type 2 fibers were predominantly involved with the strong aquaporin-4-positive rimmed vacuoles and TAR-DNA-binding protein-43 aggregations. Rimmed vacuoles with strong aquaporin-4 expression seen in the distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy patient were not found in control muscles without evidence of neuromuscular disorders and the other disease-controls. CONCLUSIONS: Aquaporin-4 might be crucial in determining the survival or degeneration of fast-twitch type 2 fibers in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy.

Ataxic hemiparesis: neurophysiological analysis by cerebellar transcranial magnetic stimulation.

The aim of this study was to investigate physiological mechanisms underlying ataxia in patients with ataxic hemiparesis. Subjects were three patients with ataxic hemiparesis, whose responsible lesion was located at the posterior limb of internal capsule (case 1), thalamus (case 2), or pre- and post-central gyri (case 3). Paired-pulse transcranial magnetic stimulation (TMS) technique was used to evaluate connectivity between the cerebellum and contralateral motor cortex. The conditioning cerebellar stimulus was given over the cerebellum and the test stimulus over the primary motor cortex. We studied how the conditioning stimulus modulated motor evoked potentials (MEPs) to the cortical test stimulus. In non-ataxic limbs, the cerebellar stimulus normally suppressed cortical MEPs. In ataxic limbs, the cerebellar inhibition was not elicited in patients with a lesion at the posterior limb of internal capsule (case 1) or thalamus (case 2). In contrast, normal cerebellar inhibition was elicited in the ataxic limb in a patient with a lesion at sensori-motor cortex (case 3). Lesions at the internal capsule and thalamus involved the cerebello-thalamo-cortical pathways and reduced the cerebellar suppression effect. On the other hand, a lesion at the pre- and post-central gyri should affect cortico-pontine pathway but not involve the cerebello-thalamo-cortical pathways. This lack of cerebello-talamo-cortical pathway involvement may explain normal suppression in this patient. The cerebellar TMS method can differentiate cerebellar efferent ataxic hemiparesis from cerebellar afferent ataxic hemiparesis.

[Two cases of posterior spinal artery syndrome (PSAS)].

We have reported two patients with posterior spinal artery syndrome. Both of them had sudden onset back pain, paraparesis, loss of deep sensation and bladder-bowel disturbances. MRI disclosed spinal cord lesions positioned at its posterior part including the posterior column or posterior horn at thoracic levels. Spinal artery syndrome is a rare disorder, especially the posterior spinal artery syndrome (PSAS). In our department, only ten patients had spinal artery syndrome out of 2,064 patients admitted to our hospital these 20 years. All the other 8 patients had anterior spinal artery syndrome. It supports the notion that PSAS is rare. The detection rate of PSAS may increase after the routine use of spinal MRI in clinical practice. Our two patients had bilateral, symmetric symptoms. These symmetric signs and symptoms are usually seen in PSAS. The bilateral posterior spinal arteries connect with each other through many complex anastomoses. Moderate blood flow insufficiency may produce no clinical symptoms because of compensation by these anastomoses. When symptoms appear, these anastomoses do not compensate blood flow deficit and may produce bilateral symptoms.

[Wernicke encephalopathy in a non-alcoholic patient with diabetic nephropathy under hemodialysis].

A 75-year-old man with diabetic nephropathy treated with hemodialysis visited to a medical office because of slight fever, and received intravenous glucose infusion without any vitamins. Thereafter, he noticed gait disturbance and began to tell inconsistent stories. He was admitted to our hospital due to aggravation of these symptoms. On admission, he was disoriented and not able to sit by himself because of severe truncal ataxia without weakness. He had also gaze direction nystagmus. Based on clinical features, we considered him as having Wernicke's encephalopathy (WE) and treated him with 100 mg thiamine per day. The thiamine supply diminished these symptoms soon. Plasma thiamine level prior to the administration was 7 ng/ml, which confirmed the diagnosis. MRI did not disclose any abnormalities frequently seen in WE. WE is a life-threatening disease, and 'early detection, early cure' is important for recovering without sequelae. The thiamine deficiency is often seen in dialysis patients because of dietary restrictions as well as its loss during dialysis. This case gives us the caution; when hemodialysis patients present acute/subacute gait disturbance and/ or abnormal mental state, we should consider WE. Furthermore, high-risk patients, such as elderly patients under hemodialysis may need some supplement including thiamine even at preclinical stage.