Multiple system atrophy (MSA) is an adult-onset, progressive neurodegenerative disorder. MSA patients show various phenotypes during the course of their illness including parkinsonism, cerebellar ataxia, autonomic failure, and pyramidal signs. MSA is classified into the parkinsonian (MSA-P) or cerebellar (MSA-C) variant depending on the clinical motor phenotype at presentation. MSA-P and MSA-C are predominant in Western countries and Japan, respectively. The mean age at onset is 55 to 60 years. Prognosis ranges from 6 to 10 years, but some cases survive for more than 15 years. Early and severe autonomic failure is a poor prognostic factor. MSA patients sometimes present with isolated autonomic failure or motor symptoms/signs, and the median duration from onset to the concomitant appearance of motor and autonomic symptoms was approximately 2 years in our previous study. As the presence of the combination of motor and autonomic symptoms is essential for the current diagnostic criteria, early diagnosis is difficult when patients present with isolated autonomic failure or motor symptoms/signs. We experienced MSA patients who died before presentation of the motor symptoms/signs diagnostic for MSA (i.e., premotor MSA). Detection of the nature of autonomic failure consistent with MSA and identification of the dysfunctional anatomical sites may increase the probability of a diagnosis of premotor MSA. Dementia is another problem in MSA. Although dementia had been thought to be rare in MSA, frontal lobe dysfunction is observed frequently during the early course of the illness. Magnetic resonance imaging can show progressive cerebral atrophy in longstanding cases. More recently, MSA patients presenting with frontotemporal dementia preceding the presence of motor and autonomic manifestations diagnostic of MSA have been reported. Novel diagnostic criteria based on an expanding concept of the clinical conditions and symptoms of MSA will be needed for the development of disease-modifying therapies and better management.

Patients with amyotrophic lateral sclerosis (ALS) often suffer from salivation problems such as drooling and dry mouth. We examined resting salivation rate cross-sectionally in 66 advanced ALS patients with tracheostomy invasive ventilation using a cotton roll method, and investigated clinical factors associated with salivation rate. Resting salivation rate in the patients was well preserved (median value 0.6 g/min), and was significantly more increased in patients with impairment of jaw movement (P = 0.007) or mouth opening (P = 0.003) than in patients with less impairment, and in patients with the mouth being constantly open ≥ 10 mm in rostrocaudal length than in patients with < 10 mm. These data indicate that salivation rate was increased with progression of dysfunction of voluntary jaw movement. Appropriate oral care is required in advanced ALS patients to maintain their oral hygiene and to avoid penetration of saliva into the airway.

A 79-year-old woman was admitted to our hospital because of prolonged impaired consciousness and right hemiparesis. She was treated for acute cerebral infarction because her brain magnetic resonance imaging showed extensive cortical lesions similar to acute infarction in diffusion weighted image, fluid attenuated inversion recovery, and T₂ weighted images. On the fifth day, she had a focal seizure on the right side. A new lesion during imaging and electroencephalogram abnormality were observed at that time. After the antiepileptic drug treatment was started, her right hemiparesis considered as ictal paresis, confusion, and the magnetic resonance imaging findings gradually improved. There was also an old, irreversible lesion in the left hippocampus, which was considered as the focus of her complex partial seizure. In the elderly, the post-ictal period of confusion, which occurs with complex partial seizure, may be prolonged. In our case, improvement of hemiparesis and confusion occurred after about 2 weeks.

We report a case of slowly progressive anti-Yo-associated paraneoplastic cerebellar degeneration (PCD) with breast cancer in a 54-year-old woman. The symptoms of limb and truncal ataxia, and dysarthria gradually progressed during the course of 1 year, and the modified Rankin scale (mRS) score was 2. A mastectomy with sentinel lymph node resection was performed for the breast cancer. No malignant cells were found on histopathological examination of the lymph node. Combination chemotherapy with adriamycin and cyclophosphamide (AC) prevented neurologic deterioration. However, subsequent treatment with trastuzumab and paclitaxel did not prevent progression of the symptoms (mRS score 3). Brain magnetic resonance imaging showed atrophy of the cerebellar hemispheres without brain stem atrophy. Anti-Yo antibody was detected in the serum, which led to a diagnosis of anti-Yo-associated PCD. We resected an enlarged axillary lymph node, which was found on computed tomography. The histopathological analysis of the lymph node revealed foreign body granuloma, which suggested an association with necrotic malignant tissue. Following additional tegafur-uracil therapy and two courses of intravenous immunoglobulin (IVIg), the cerebellar signs and symptoms gradually improved (mRS score 2). The clinical course shows that PCD can present as a slowly progressive cerebellar symptom. We propose an active treatment for anti-Yo-associated PCD consisting of tumor resection, combined chemotherapy, and IVIg.

A 65 year-old woman with small lymphocytic leukemia presented with subacute cerebellar ataxia. Six months after rituximab chemotherapy, a cranial MRI revealed lesions in the bilateral middle cerebellar peduncles. Both cerebrospinal fluid (CSF) JC virus (JCV)-DNA PCR test on three occasions and brain biopsy were negative. CSF tests were repeated. The fourth test performed 6 months after the onset showed positive JCV-DNA, and a definite diagnosis of progressive multifocal leukoencephalopathy (PML) was made. Neuroimaging of cerebellar atrophy was considered to be coexistence of granule cell neuronopathy. Medication with mirtazapine and mefloquine was temporarily effective for several months. Little are known solitary bilateral MRI lesions of the middle cerebellar peduncle in PML. JCV-PCR test of CSF may be negative at an earlier stage of PML. Repeated CSF tests should be essential to confirming the diagnosis in such cases.

A 74-year-old female patient, who was diagnosed with neurofibromatosis type 1 (NF1) at the age of 40, was admitted with complaints of flickering vision and gait disturbance for the last 2 years. On admission, neurological examination revealed mild bilateral hearing loss and ataxia in the limb and trunk. Laboratory tests revealed anti-hepatitis C virus (HCV) antibody positivity and elevated HCV RNA by real-time polymerase chain reaction. The cerebrospinal fluid examination revealed a slightly yellowish appearance with elevated total protein levels. Gradient echo T₂*-weighted brain magnetic resonance imaging (MRI) demonstrated a rim of hypointense lesions surrounding the surface of the cerebellum, brainstem, frontal and temporal lobes, and thalamus, which was considered as hemosiderin depositions. From these MRI findings, she was diagnosed as having superficial siderosis of the central nervous system. Cerebral angiography revealed an aneurysm-like dilatation at the bifurcation of the right internal carotid-posterior communicating artery. ^99mTc-ethyl cysteinate dimer single-photon emission computed tomography revealed hypoperfusion in the bilateral frontal and temporal lobes. Pelvic plain X-ray, pelvic computed tomography, and lumbosacral MRI revealed a sacral defect and an anterior sacral polycystic meningocele communicating with the spinal subarachnoid space. The patient’s symptoms gradually worsened, and she died of septic shock because of pyelonephritis at the age of 77. An autopsy was performed; on pathological examination, we did not observe any findings associated with rupture of the aneurysm-like dilatation in the bifurcation of the right internal carotid-posterior communicating artery and cerebral amyloid angiopathy. Because duropathies—a new neurological disease concept—have been implicated as a cause of bleeding in the superficial siderosis, the anterior sacral polycystic meningocele, a type of duropathies, was presumed to be the most probable bleeding source of the superficial siderosis in this patient. Bleeding from the meningocele might result from the vulnerability of vessel walls in NF1.

A 38-year-old man visited our hospital because of hemifacial paresis that developed 2 months after being bit by a tick. We diagnosed idiopathic peripheral facial palsy and gave the patient oral prednisolone and valacyclovir. Although the symptoms completely resolved in about 2 weeks, there was a risk of Lyme neuroborreliosis. The patient therefore received doxycycline (100 mg twice daily) and amoxicillin (1,000 mg 3 times daily) for 14 days. Two months later, he had symptoms of meningitis such as headache and fever accompanied by lymphocytic cerebrospinal fluid pleocytosis. Viral meningitis was diagnosed and treated with parenteral acyclovir. The symptoms of meningitis improved. Tests for serum IgG antibodies against borrelia were positive. We gave the patient a diagnosis of Lyme neuroborreliosis. The patient received intravenous ceftriaxone and had no relapse. It is a rare for meningitis to develop in a patient with cranial neuropathy who received doxycycline. Lyme neuroborreliosis is a rare disease in Japan. Care should therefore be exercised in the diagnosis of Lyme neuroborreliosis and evaluation of the response to treatment.

An 86-year-old woman with a one-year history of dementia was admitted to our hospital complaining of loss of appetite, hallucinations, and disturbance of consciousness. She gradually presented with chorea-like involuntary movements of the extremities. Diffusion-weighted magnetic resonance imaging (MRI) showed bilateral symmetrical hyperintense signals in the basal ganglia. The serum vitamin B₁₂ level was below the lower detection limit of 50 pg/ml. The homocysteine level was markedly elevated at 115.8 nmol/ml. Anti-intrinsic factor and anti-parietal cell antibody tests were positive. Gastrointestinal endoscopy revealed atrophic gastritis. The patient was diagnosed with encephalopathy due to vitamin B₁₂ deficiency caused by pernicious anemia. Involuntary movements and MRI abnormalities improved with parenteral vitamin B₁₂ supplementation. Bilateral basal ganglia lesions are rare manifestations of adult vitamin B₁₂ deficiency. The present case is considered valuable in identifying the pathophysiology of involuntary movement due to vitamin B₁₂ deficiency.

An 81-year-old woman suffering from sarcoidosis, chronic renal failure caused by hypertention was treated by valacyclovir 500 mg/day, for the diagnosis of herpes zoster of her right back. Her consciousness gradually became worse, and 3 days after taking the drug, she was sent to the emergency department of the hospital. Her conscious level was E2V2M5 (Glasgow Coma Scale) and myoclonus especially in her lower extremities occurred. Head CT and MRI show no obvious, acute abnormal findings other than chronic ischemic lesions, while an electroencephalogram (EEG) shows periodic synchronous discharges (PSDs) and disorganized background activity. Based on these findings, she was diagnosed as valacyclovir-associated acute encephalopathy. After conservative therapy of maintenance hemodialysis, her consciousness gradually improved, and PSDs disappeared accordingly and background activity of EEG became improved. In this case report, we presented valacyclovir-associated neurotoxicity with PSDs in EEG as potentially a surrogate marker. We should be cautious to use valaciclovir which may cause drug-induced encephalopathy especially in elderly or patients with renal failure even though the dose was adjusted in advance.