New and reliable MRI diagnosis for progressive supranuclear palsy.

OBJECTIVE: To evaluate the area of the midbrain and pons on mid-sagittal MRI in patients with progressive supranuclear palsy (PSP), Parkinson disease (PD), and multiple-system atrophy of the Parkinson type (MSA-P), compare these appearances and values with those of normal control subjects, and establish diagnostic MRI criteria for the diagnosis of PSP. METHODS: The authors prospectively studied MRI of 21 patients with PSP, 23 patients with PD, 25 patients with MSA-P, and 31 age-matched normal control subjects. The areas of the midbrain tegmentum and the pons were measured on mid-sagittal MRI using the display tools of a workstation. The ratio of the area of the midbrain to the area of the pons was also evaluated in all subjects. RESULTS: The average midbrain area of the patients with PSP (56.0 mm2) was significantly smaller than that of the patients with PD (103.0 mm2) and MSA-P (97.2 mm2) and that of the age-matched control group (117.7 mm2). The values of the area of the midbrain showed no overlap between patients with PSP and patients with PD or normal control subjects. However, patients with MSA-P showed some overlap of the values of individual areas with values from patients with PSP. The ratio of the area of the midbrain to the area of pons in the patients with PSP (0.124) was significantly smaller than that in those with PD (0.208) and MSA-P (0.266) and in normal control subjects (0.237). Use of the ratio allowed differentiation between the PSP group and the MSA-P group. CONCLUSION: The area of the midbrain on mid-sagittal MRI can differentiate PSP from PD, MSA-P, and normal aging.

[Respiratory failure due to diaphragmatic dysfunction in Charcot-Marie-Tooth disease: a case report].

A 56-year-woman with type 2 respiratory failure due to diaphragmatic dysfunction in Charcot-Marie-Tooth disease (CMT) is reported. The patient, who had a 50-year history of CMT, was referred to our hospital because of nocturnal dyspnea. Arterial blood gas analysis on admission showed marked hypoxia with hypercapnia, and physical examination revealed thoracoabdominal paradoxus in the supine position. Chest radiography revealed elevation of both sides of the diaphragm. The vital capacity and arterial blood gas pressure in the sitting position were markedly higher than those in the supine position. Electrical phrenic nerve stimulation failed to produce any convincing muscle action potential in the diaphragm. These findings suggested that her respiratory failure was induced by both diaphragmatic dysfunction caused by bilateral phrenic nerve palsy due to CMT. Treatment of this patient was started at home with a pressure support ventilator, resulting in satisfactory clinical improvement. In general, respiratory muscle impairment is a rare phenomenon in a patient with CMT. However when a patient with CMT complains of dyspnea or if unexpected heart failure develops, it is important to keep in mind that CMT may be associated with phrenic nerve palsy.

[Central necrosis of the lumbo-sacral segment of the spinal cord associated with multiple cholesterin emboli, clinically presenting as acute paraplegia].

A seventy-six-year-old man suddenly suffered from paraplegia and pain in both legs. He had been maintained on hemodialysis and committed a suicide attempt by cutting the shunt at the paraplegic attack. He was brought to the emergency ward for the treatment of hemorrhagic preshock. Neurological examination demonstrated flaccid paraplegia, loss of tendon reflex in the lower extremities, dissociated sensory loss below the fourth lumbar level; and incontinence in defecation. MRI showed T2 shortening in the ventral spinal cord caudal below the level of the eleventh thoracic cord. Postmortem examination confirmed ischemic infarct in the central area of the spinal cord, associated with disseminated cholesterin emboli in the small arteries. This case was the first MRI demonstration of central necrosis caused by cholesterin emboli, and may emphasize the significance of cholesterin emboli in the spinal arterial disorders in the aged.

Familial parkinsonism and dementia with ballooned neurons, argyrophilic neuronal inclusions, atypical neurofibrillary tangles, tau-negative astrocytic fibrillary tangles, and Lewy bodies.

We report four patients with a new type of familial parkinsonism and dementia consisting of an autosomal dominant inheritance, dopa-responsive parkinsonism, severe dementia, variable myoclonus and autonomic disturbances. Autopsy of two patients revealed symmetrical cerebral atrophy with fronto-temporal dominant distribution, and marked depigmentation in the substantia nigra and locus ceruleus. Neuronal loss and gliosis were observed in the deep cerebral cortex and amygdala as well as in the areas vulnerable to Parkinson's disease. In the cerebral cortex, swollen neurons with frequent granulovacuolar changes were observed, consisting of ballooned neurons and those with argyrophilic intracytoplasmic inclusions, in addition to neuropil threads. Atypical neurofibrillary tangles, which barely stained with tau antibodies, were numerous in the upper cortical layers, consisting of 15-nm straight tubules. In addition, tau-negative astrocytic fibrillary tangles were also frequent. Electron microscopically, the ballooned neurons and argyrophilic neuronal inclusions contained filamentous structures coated with fuzzy electron-dense deposits. The inclusions showed immunohistochemical features different from those of cortical Lewy bodies and Pick bodies. Occasional Lewy bodies were present in the brain stem lesions of both patients. In two of our patients, the pathology in the brain stem was similar to that of Parkinson's disease, whereas their cerebral pathology was unusual and has not been reported previously.

Facial nerve enhancement on gadolinium-DTPA in a case with neurosarcoidosis.

In a case of neurosarcoidosis with bilateral facial nerve palsy and hydrocephalus, contrast-enhanced magnetic resonance imaging (MRI) study and angiotensin converting enzyme (ACE) activities in cerebrospinal fluid (CSF) were valuable for the diagnosis and the follow up. Facial nerve lesions were demonstrated on gadolinium-DTPA enhanced MRI. The disappearance of enhancement was concomitant with the amelioration of facial nerve palsy after corticosteroid therapy.

The T-C(8356) mitochondrial DNA mutation in a Japanese family.

A rare point mutation at nucleotide position 8356 in the transfer RNA gene in mitochondrial DNA was found in a Japanese family. Our proband had migraine and dementia associated with lactic acidosis in addition to myoclonic epilepsy with ataxia and ragged-red fibres in a muscle biopsy specimen consistent with the clinical characteristics of myoclonic epilepsy with ragged-red fibres (MERRF). His mother, who had the same point mutation, also had migraine but without myoclonus or ataxia. His aunt, who had the same point mutation and migraine, developed diabetes mellitus, encephalomyopathy and several stroke-like episodes associated with lactic acidosis (MELAS). This is the third family with the rare mutation seen in American and Italian families. The mutation may not be specific to Caucasians, and is probably closely related to the MERRF/MELAS overlap syndrome.

Cerebral metabolism of oxygen and glucose in a patient with MELAS syndrome.

We studied cerebral oxygen and glucose metabolism as well as cerebral blood flow using positron emission tomography (PET) in a case with MELAS showing dementia, diabetes mellitus, ataxia and lactic acidosis without any signs of stroke. This case, confirmed to have a point mutation at position 3243 in the transfer RNA gene of mitochondrial DNA, developed a stroke-like episode 8 months after the PET study. Uncoupling was observed between cerebral oxygen metabolism and cerebral blood flow with reduced fractional oxygen extraction ratio, indicating "hyperemia", not ischemia. The "hyperemia" may be closely related to the malfunction of mitochondria in aerobic energy production. A drastic decrease in cerebral oxygen metabolism (CMRO2) was found globally in contrast to preserved cerebral glucose metabolism (CMRglu), resulting in a remarkable decrease in the metabolic ratio (CMRO2/CMRglu). The dissociation between cerebral glucose and oxygen metabolism may be characteristic of MELAS.

Fatal respiratory failure due to polymyositis.

A patient presenting as severe respiratory failure due to alveolar hypoventilation resulting from respiratory muscle weakness is described. Diagnosis of polymyositis was established by electromyography and muscle biopsy. Steroid therapy was initiated and it ameliorated respiratory failure remarkably. Selective respiratory muscle involvement due to polymyositis has been suggested in this patient. Although fatal respiratory failure is a very rare complication in polymyositis, polymyositis should be considered as one of underlying diseases causing severe respiratory failure.