杉山 淳比古

BACKGROUND: Acute intermittent porphyria (AIP) is a rare but treatable disease. COVID-19 has various possible complications including posterior reversible encephalopathy syndrome (PRES). COVID-19 was reported to trigger an acute attack in patients with acute hepatic porphyria (AHP). The pathophysiology of AHP-associated PRES is not fully elucidated. CASE PRESENTATION: A 31-year-old Vietnamese female initially presented with seizures, severe hyponatremia, and hypertension after COVID-19. Despite the initial treatment, she had recurrent seizures and developed PRES as confirmed by magnetic resonance imaging. Further investigations revealed a genetic mutation of c.517 C > T in HMBS, leading to a diagnosis of AHP. Treatment with hemin significantly improved her symptoms and corrected her electrolyte imbalance. CONCLUSIONS: This case highlights the potential for COVID-19 to trigger acute attacks in patients with underlying porphyria, potentially leading to complications such as PRES. Also, we observed elevated catecholamine levels during an acute porphyria attack and PRES, suggesting their involvement in the pathogenesis of AIP-associated PRES. Clinicians should consider the possibility of porphyria in patients with COVID-19-associated PRES, especially when they present with gastrointestinal and neuropsychiatric symptoms.

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.

Multiple system atrophy (MSA) is a progressive, incurable neurodegenerative disease characterized by the risk of sudden death and various symptoms, including autonomic and cognitive dysfunction, as well as motor symptoms such as cerebellar ataxia and parkinsonism. These clinical features make the diagnosis of MSA challenging for neurologists. Our questionnaire survey on the delivery of an MSA diagnosis revealed that 92.3% of the participating neurologists found it difficult to deliver the diagnosis. However, 82.8% perceived explaining the risk of sudden death to be challenging. Factors independently associated with difficulties in delivering a diagnosis included perceived challenges in the differential diagnosis of MSA, conveying information about the risk of sudden death, and explaining the importance of the family's decision-making process in life-prolonging treatment. Further research is required to develop guidelines for delivering the diagnosis of MSA.

OBJECTIVES: This study aimed to investigate cerebrospinal fluid (CSF) adenosine deaminase (ADA) levels in various neurological disorders and examine the relationships between CSF ADA levels and immunological parameters. METHODS: Overall, 276 patients whose CSF ADA levels were measured for suspected tuberculous meningitis (TBM) were evaluated. Data on baseline characteristics, final diagnoses, CSF ADA levels, and other laboratory parameters were collected. Thereafter, CSF ADA levels were compared based on final diagnoses, and correlations between CSF ADA levels and other CSF and blood laboratory parameters were evaluated. RESULTS: Five diseases exhibited a significant increase in CSF ADA levels relative to the noninflammatory disease control group (n = 40): (1) TBM (n = 15, p < 0.0001), (2) fungal meningitis (n = 7, p = 0.0400), (3) autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A, n = 7, p < 0.0001), (4) neurosarcoidosis (n = 7, p = 0.0028), and (5) lymphoproliferative disorders (n = 18, p = 0.0001). Strong positive correlations were observed between CSF ADA and CSF parameters, including soluble IL2 receptor (rs = 0.7566, p < 0.0001), albumin (rs = 0.6693, p < 0.0001), lactate dehydrogenase (rs = 0.6452, p < 0.0001), white blood cell count (rs = 0.6035, p < 0.0001), protein (rs = 0.6334, p < 0.0001), and lymphocytes (rs = 0.5954, p < 0.0001). DISCUSSION: CSF ADA levels were elevated in various inflammatory neurological diseases, especially in TBM, fungal meningitis, GFAP-A, neurosarcoidosis, and lymphoproliferative disorders. CSF ADA levels may reflect T-cell hyperactivation in the central nervous system.