Spinal cord herniation: a missing piece in the pathogenesis of amyotrophic lateral sclerosis and multiple sclerosis?

BACKGROUND: Idiopathic spinal cord herniation (SCH) is a rare and often misdiagnosed condition characterized by displacement of the spinal cord through an anterior defect of the dural sac. This condition determines continuous focal trauma of the spinal cord, causing slowly progressive myelopathy. The peculiar MR scan findings, particularly sagittal T(2)-weighted images, allow its recognition. OBJECTIVE: Herein, we report 3 cases of SCH and suggest a possible association with trauma-related neurodegenerative or chronic inflammatory diseases. METHODS: We reviewed the clinical files of all patients admitted to our hospital with a history and signs of progressive myelopathy (paraparesis and/or lower extremity hypoesthesia) who were diagnosed with SCH by MRI. RESULTS: We found 3 female patients (37, 69 and 68 years of age) with a diagnosis of SCH. Two of them presented with concomitant, relatively rare disabling neurological diseases, namely amyotrophic lateral sclerosis and multiple sclerosis. The third patient underwent surgery and gradually recovered over 6 months. CONCLUSIONS: Persistent central nervous system trauma due to idiopathic SCH might provide an unexpected hint about the pathogenesis of amyotrophic lateral sclerosis and multiple sclerosis.

Neurosarcoidosis. Clinical description of 7 cases with a proposal for a new diagnostic strategy.

OBJECTIVE: Chronic involvement of the nervous system is relatively rare in sarcoidosis. We describe 7 cases that fulfil Zajicek's criteria for neurosarcoidosis (NS) and propose some modifications to such criteria. MATERIALS AND METHODS: The patients were admitted for various neurological syndromes: 2 cases presented with chronic lymphocytic meningitis, 4 with spinal cord symptoms, one case was initially confused with multiple sclerosis. Serological tests, immunological screening, cerebrospinal fluid (CSF) analysis, bacteriological and viral testing were performed in all patients. Spinal and cerebral MRI, gallium scan, bronchoscopy with biopsy and bronchoalveolar-lavage fluid analysis, high-resolution computed tomography (HRCT) of the chest, biopsy of the lungs, skin, mediastinal lymph-node and meninges, were useful in diagnosing NS. RESULTS AND DISCUSSION: Laboratory tests showed serum inflammatory abnormalities, but were negative for infectious diseases, while CSF showed inflammatory signs in all patients. MRI revealed meningeal enhancement or hypertrophic pachymeningeal lesions in 4 patients, white matter abnormalities and mass lesions in 2 patients, and a spinal mass lesion in 1 patient. Gallium scan, HRCT, bronchoscopy were positive in most cases. Patients were treated with steroid and immunosuppressive therapy, with improvement in six cases. One patient died from infectious complications. CONCLUSION: A definite diagnosis of NS requires demonstration of non-caseating granulomas affecting nervous tissues. In most cases, histological evidence of systemic disease (probable NS) is sufficient in the presence of compatible alterations in the CNS. In our patients the bronchoalveolarlavage fluid analysis, gallium scan, and chest HRCT were important for diagnosis, while serum ACE was always normal and chest radiographs were not suggestive of sarcoidosis.