澁谷 和幹

Rigidity, a cardinal symptom of Parkinson's disease (PD), remains challenging to assess objectively. A torque-angle instrument was developed to quantify muscle tone, providing two parameters: bias difference and elastic coefficient. This study aimed to investigate the association of the instrument-measured rigidity with clinical assessments and brain function. In 30 patients with PD, the muscle tone in both arms was evaluated. Ten with wearing-off phenomenon were assessed twice, off and on condition. Twentynine patients underwent brain perfusion single-photon emission computed tomography (SPECT), and expression of PD-related covariance pattern (PDRP) was computed. Bias difference and elastic coefficient showed positive correlations with physician-rated rigidity (P < 0.002). Bias difference decreased after dopaminergic medication (P = 0.022) and was associated with lower body mass index (P = 0.012). Elastic coefficient positively correlated with the Unified PD Rating Scale Part III and PDRP scores (P < 0.044). Furthermore, the higher bias difference correlated with decreased sensory-motor cortex and increased substantia nigra perfusion (P < 0.001). The Torque-angle instrument is a viable tool for quantifying rigidity in PD. The bias difference reflects treatment responsiveness and is associated with the function in the sensory-motor cortex and substantia nigra. The elastic coefficient is indicative of overall Parkinsonism severity.

OBJECTIVES: Intrathecal baclofen (ITB) therapy is well documented as an effective treatment option for severe spasticity. Before ITB implantation, trials are conducted to evaluate efficacy, safety, and candidate suitability. While many centers conduct ITB trials, appropriate physical assessment has not been fully established. This study aimed to identify useful physical assessments for ITB trials in spastic paraparesis. MATERIALS AND METHODS: Patients with spasticity who experienced paraplegia for at least 12 months and underwent ITB trials in Chiba University Hospital were included. Physical functions were assessed before ITB administration and 4 hours after ITB injection on each day of the ITB trial. Physical assessments included targeted neurological and musculoskeletal tests (modified Ashworth scale, deep tendon reflexes, clonus, active range of motion, and manual muscle test) and mobility tests (Berg Balance Scale, Timed Up and Go Test [TUG], 10-Meter Walk Test, and step length). RESULTS: A total of 22 patients underwent ITB trials. Among the physical assessments, the Modified Ashworth Scale, reflexes, clonus, active range of motion at hip abduction and ankle dorsiflexion, TUG, and step length showed significant differences between the assessments conducted before and during ITB trials. Conversely, active range of motion in most joints, the manual muscle test, and the 10-Meter Walk Test did not show significant differences. The total score of the Berg Balance Scale did not show significant differences, whereas only the item of "placing alternate foot on stool" was significantly different. CONCLUSIONS: Spasticity assessments, including the Modified Ashworth Scale and reflexes, and mobility assessments such as TUG and step length, were useful for detecting the effectiveness of ITB screening for spastic paraparesis. The TUG may be particularly suitable for detecting effects, as it is a quantitative and reliable measure that reflects actual movement in daily living activities.

BACKGROUND: The efficacy of deep brain stimulation (DBS) in treating tremor symptoms in cerebellar disorders remains unclear. CASE PRESENTATION: A 47-year-old woman presented with neck and arm tremor and ataxic speech/gait after four days of >40 °C fever due to septic shock attributed to lithiasis-pyelonephritis. Left ventral intermediate nucleus thalamus DBS alleviated contralateral postural arm tremor, although the action tremor and terminal oscillation remained unchanged. DISCUSSION: To our knowledge, this is the first report of thalamic DBS for hyperthermia-induced cerebellar dysfunction. Patients with postural tremor resulting from cerebellar damage can benefit from thalamic DBS, leading to improved activities of daily living.

BACKGROUND: Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease, is an autosomal dominant neurodegenerative disorder caused by CAG repeat expansion in exon 10 of ATXN3. Extra-cerebellar manifestations, including external ophthalmoplegia, dystonia, Parkinsonism, and peripheral neuropathy, are predominantly present in SCA3 cases. Here, we report a case of SCA3 presenting with a split hand and minipolymyoclonus. CASE PRESENTATION: A 73-year-old female patient presented with a 5-year history of ataxic gait. Neurological examination revealed cerebellar ataxia and minipolymyoclonus in the digits on both sides and muscle atrophy in the right hand, consistent with the split hand pattern. Electrodiagnostic studies demonstrated decreased amplitude of compound muscle action potentials and neurogenic motor unit potentials, indicating lower motor neuron involvement. CONCLUSIONS: Our patient's case indicated a split hand and minipolymyoclonus in SCA3. Clinicians should consider these extra-cerebellar manifestations in patients with SCA3. Although neither split hand nor minipolymyoclonus are likely to directly result in a specific etiological diagnosis, a common pathophysiological mechanism for both may be lower motor neuron involvement. This extracerebellar manifestation contributes to narrowing down the diagnostic possibilities for cases presenting with progressive cerebellar ataxia.