Disinhibited Blink Reflex Recovery Is Related to Lateral Trunk Flexion in Parkinson Disease.

PURPOSE: Lateral trunk flexion is often observed in patients with Parkinson disease (PD) and causes poor quality of life. Asymmetrical function of the basal ganglia is believed to be the main cause of lateral trunk flexion, and dysfunction of the basal ganglia facilitates the blink reflex by disinhibiting the spinal trigeminal nucleus. Our aim was to investigate whether a disinhibited blink reflex recovery curve (BRrc) was associated with lateral trunk flexion in PD patients. METHODS: We enrolled 21 PD patients, including 11 with marked lateral trunk flexion (F-PD) and 10 with normal posture (N-PD), and 10 normal controls. Blink reflex recovery curves at interstimulus intervals of 200, 300, and 500 ms were compared between F-PD, N-PD, and normal controls. RESULTS: The BRrc in F-PD patients was more disinhibited than in N-PD patients and controls, and this disinhibition was asymmetrical. CONCLUSIONS: The asymmetrically disinhibited BRrc in F-PD patients was associated with lateral trunk flexion. This is the first neurophysiological study of patients with PD with abnormal posture. Examination of the BRrc may permit early detection of asymmetrical basal ganglia dysfunction that can eventually cause lateral trunk flexion.

Spinal cord anteroposterior atrophy in HAM/TSP: Magnetic resonance imaging and neuropathological analyses.

To evaluate the spinal cord atrophy that occurs in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), we conducted magnetic resonance imaging (MRI) and pathological analyses. In the MRI study, 15 patients with HAM/TSP and 20 age-matched normal control subjects were enrolled. Anteroposterior and transverse distances and cross-sectional areas were measured and calculated at the C2, C4, C6, T2, and T6 vertebral levels. In the pathological study, spinal cord autopsy specimens were compared between a HAM/TSP case and an adult T cell leukemia/lymphoma case. In both the MRI and pathological studies, HAM/TSP spinal cords demonstrated more severe atrophy in the anteroposterior direction than those of controls. The spinal cord atrophy and pathological changes in HAM/TSP occurred predominantly in the white matter, especially in the lateral columns. This is the first report indicating spinal cord atrophy in the anteroposterior direction using MRI. In pathological analysis, atrophy and pathological changes were prominent in areas of the spinal cord with slow blood flow. Hemodynamic and anatomical factors are speculated to be among the main mechanisms of atrophy in the anteroposterior direction.

Sensory axonal polyneuropathy due to 2,4-dinitrophenol.

A 24-year-old man developed subacute onset of numbness and pain in the upper and lower limbs. Physical examination demonstrated decreased pinprick sensation, but was otherwise normal. Blood and cerebrospinal fluid parameters were normal except for mild hepatic dysfunction. No data were suggestive of connective tissue disease. Nerve conduction studies demonstrated sensory neuropathy. A detailed medical interview revealed that the patient had been taking self-imported 2,4-dinitrophenol (DNP) for 2 months to decrease body weight. Six months after discontinuing DNP, subjective symptoms and liver dysfunction resolved completely, and the patient was diagnosed with drug-induced peripheral neuropathy and hepatopathy. There are no case reports of health risks posed by DNP in Japan, and even worldwide, cases of peripheral neuropathy due to DNP are rare. Obtaining a detailed drug history is important, as is providing information on the dangers of self-imported medicines.

Prolonged central sensory conduction time in patients with chronic arsenic exposure.

BACKGROUND: Many patients from Toroku, Japan, who have chronic arsenic exposure demonstrate whole-body sensory disturbance that is slightly more pronounced in the extremities. Although previous research in this population showed a mild peripheral neuropathy, it is unknown whether these patients have central nervous system impairment. To investigate the lesion sites underlying sensory disturbance related to chronic arsenic poisoning, we analyzed somatosensory evoked potentials (SEP). METHODS: Clinical features, nerve conduction study results, and median and/or tibial SEP were analyzed in patients with chronic arsenic exposure (total, 13 patients; median & tibial, 4; median, 5; tibial, 4) retrospectively. The SEP findings in patients were compared with those in normal controls. RESULTS: The median SEP results indicated a conduction delay between the proximal brachial plexus and the primary sensory cortex, and tibial SEP findings indicated a delay between the dorsal gray matter of the lumbosacral cord and the primary sensory cortex. CONCLUSION: This is the first study to identify an impairment of the central somatosensory pathway in patients with chronic arsenic exposure. Sensory disturbance in these patients is related not only to peripheral neuropathy but also to impairment of the central nervous system.

Increased body mass index associated with autonomic dysfunction in Parkinson's disease.

BACKGROUND: The association between Parkinson's disease (PD) and body mass index (BMI) has not been established. In this study, we investigated the correlation between BMI and autonomic dysfunction in patients with PD. METHODS: Clinical features, BMI, cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigraphy and the coefficient of variation of the electrocardiographic R-R interval (CVRR) were analyzed in 124 patients with PD who were naïve to anti-parkinsonian drugs. RESULTS: BMI was negatively correlated with early heart-to-mediastinum ratio and CVRR in patients with PD, regardless of disease duration and severity. CONCLUSIONS: Autonomic dysfunction and BMI increase were associated with each other. Physicians should consider the possibility of autonomic dysfunction in PD patients with high BMI.

PR Prolongation and Cardiac 123I-MIBG Uptake Reduction in Parkinson's Disease.

BACKGROUND: Cardiac 123I-metaiodobenzylguanidine scintigraphy (MIBG) previously demonstrated an uptake reduction in patients with Parkinson's disease (PD). However, epidemiologic research showed that electrocardiography (ECG) abnormalities occurred prior to motor signs in PD. Here we investigated whether the electrical conduction system of the heart was impaired in PD. METHODS: Clinical features, ECG and MIBG parameters were analyzed in 191 patients with PD, 42 with multiple system atrophy (MSA) and 124 normal controls (NL). RESULTS: The PR interval was significantly longer in patients with PD than in NL. The PR interval was significantly negatively correlated with early and delayed heart-to-mediastinum ratios in MIBG scintigraphy in PD and MSA patients. In 19 PD patients with PR prolongation, 17 patients also had abnormal MIBG findings, and the other 2 showed normal MIBG. CONCLUSIONS: The PR prolongation must show some sympathetic system abnormality because it is mainly controlled by the sympathetic nervous system. PR prolongation supports the objective biomarker value of MIBG for PD diagnosis.

Hypometabolism of watershed areas of the brain in HTLV-1-associated myelopathy/tropical spastic paraparesis.

In previous studies of human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), areas of slow blood flow in the spinal cord were related to pathological changes. While the pathological changes in the brain are milder than those in the spinal cord, they are also more significant in sites with slow blood flow. In this study, we investigated brain glucose metabolism in slow blood flow areas using fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET). Clinical features and brain (18)F-FDG-PET parameters were analyzed in six patients with HAM/TSP. For comparison of PET data, eight healthy volunteers were enrolled as normal controls (NLs). Glucose metabolism in the watershed areas of the middle and posterior cerebral arteries, as compared with that in the occipital lobes as a control, was significantly lower in HAM/TSP patients than in NLs. This result confirmed the relationship between slow blood flow areas and hypometabolism in HAM/TSP, and is consistent with previous findings that pathological changes are accentuated in sites with slow blood flow.

[A case of neurolymphomatosis: peripheral neuropathy induced by diffuse large B-cell lymphoma without any abnormal accumulation observed on early positron emission tomography-computed tomography].

A 64-year-old woman with diffuse large B-cell Lymphoma (DLBCL) complained of double vision and pain sensation in her limbs after eight cycles of chemotherapy. F-fluorodexyglucose-positron emission tomography (FDG-PET) 7 days after the onset of double vision showed no abnormal accumulation and confirmed remission of DLBCL according to the international criteria. However, she developed limb weakness and severe paresthesia. The second FDG-PET 41 days after onset showed increased uptake at the both the brachial and lumbar plexuses, suggesting neurolymphomatosis. Although FDG-PET appears to be a highly sensitive diagnostic method for neurolymphomatosis, it is sometimes difficult to detect neurolymphomatosis in early diagnose, such as with this case. Therefore, multiple examinations are necessary to determine neurolymphomatosis.

Severe Orthostatic Hypotension due to Unilateral Carotid Artery Dissection.

A 46-year-old woman was admitted to our hospital with mild right-sided hemiparesis and orthostatic hypotension. Magnetic resonance angiography of the neck showed stenosis of the left distal carotid sinus surrounded by intraluminal hyperintensities on both T1-weighted and T2-weighted images, representing a periluminal hematoma secondary to carotid artery dissection. The dissection hyper-extended the carotid artery wall and stimulated baroreceptors in the carotid sinus. The stimulated baroreceptors induced carotid sinus hypersensitivity, which may have been related to her orthostatic hypotension. Post-stroke orthostatic hypotension should prompt consideration of carotid artery dissection.

[Bilateral sensorineural hearing impairment due to Streptococcus suis meningitis 20 days after swine bite].

Streptococcus suis (S. suis) is a zoonotic pathogen in pigs, which can be transmitted to humans by close contact. Meningitis is the most common clinical manifestations of S. suis infection and hearing impairment is a frequent complication. The risk of S. suis meningitis is higher in people who work in the swine industry. The patient was a 53-year-old woman working in the swine industry, who developed headache and fever 20 days after a swine bite. She was diagnosed as meningitis and S. suis was detected in the cerebrospinal fluid. We treated her with ceftriaxone, vancomycin, and dexamethasone, and signs of meningeal irritation diminished three days after admission. However, bilateral sensorineural hearing impairment occurred on the ninth day after admission. We added methylprednisolone (500 mg, 2 days) but moderate hearing impairment remained on the left. Antibiotic therapy should be considered for wounds of people involved in the swine industry for preventing S. suis infection.When S. suis meningitis occurs, symptoms of hearing impairment must be monitored carefully.