Ocular Motor Dysfunction due to Multiple Sclerosis.

Ocular motor disorders are common in patients afflicted by multiple sclerosis. We present a particularly complex case of multifaceted ocular motor dysfunction as it illustrates the arcane associated neuroanatomy and the interplay between ocular motor systems in the brainstem, midbrain, and cerebellum.

Neuroimaging comparison of primary progressive apraxia of speech and progressive supranuclear palsy.

BACKGROUND AND PURPOSE: Primary progressive apraxia of speech, a motor speech disorder of planning and programming, is a tauopathy that has overlapping histological features with progressive supranuclear palsy. We aimed to compare, for the first time, atrophy patterns, as well as white matter tract degeneration, between these two syndromes. METHODS: Sixteen primary progressive apraxia of speech subjects were age- and gender-matched to 16 progressive supranuclear palsy subjects and 20 controls. All subjects were prospectively recruited, underwent neurological and speech evaluations and 3.0-Tesla magnetic resonance imaging. Grey and white matter atrophy was assessed using voxel-based morphometry and atlas-based parcellation, and white matter tract degeneration was assessed using diffusion tensor imaging. RESULTS: All progressive supranuclear palsy subjects had typical oculomotor/gait impairments, but none had speech apraxia. Both syndromes showed grey matter loss in supplementary motor area, white matter loss in posterior frontal lobes and degeneration of the body of the corpus callosum. Whilst lateral grey matter loss was focal, involving superior premotor cortex, in primary progressive apraxia of speech, loss was less focal extending into prefrontal cortex in progressive supranuclear palsy. Caudate volume loss and tract degeneration of superior cerebellar peduncles were also observed in progressive supranuclear palsy. Interestingly, area of the midbrain was reduced in both syndromes compared to controls, although this was greater in progressive supranuclear palsy. CONCLUSIONS: Although neuroanatomical differences were identified between these distinctive clinical syndromes, substantial overlap was also observed, including midbrain atrophy, suggesting these two syndromes may have common pathophysiological underpinnings.

Neuroanatomical correlates of the progressive supranuclear palsy corticobasal syndrome hybrid.

BACKGROUND: The progressive supranuclear palsy syndrome (PSPS) and corticobasal syndrome (CBS) are associated with relatively specific patterns of atrophy; the former predominantly involving the brainstem, the latter frontoparietal regions. However, it has become apparent that there are subjects that meet criteria for PSPS and CBS. We refer to subjects with this presentation as Hybrids. The hybrid presentation is not rare, yet there are no studies that have assessed the neuroanatomical correlates of the hybrid syndrome to explain its occurrence. METHOD: In this study of 41 subjects and controls, we utilized the technique of voxel-based morphometry to assess both gray and white matter volume loss in six prospectively recruited Hybrids that underwent 3.0 T volumetric head magnetic resonance image scanning to determine the neuroanatomical correlates of the syndrome. We compared patterns of atrophy in three prospectively recruited groups: the Hybrid group (n = 6), a PSPS group (n = 10), and CBS group (n = 5). All 21 subjects had completed the same standardized batteries assessing cognition, and motor, behavioral, executive, oculomotor and limb praxis function. RESULTS: The Hybrid group showed imaging features of both PSPS and CBS, with volume loss observed in the brainstem (superior cerebellar peduncle) and cortex (medial and lateral premotor, prefrontal and motor cortex). As expected, typical patterns of loss were observed in PSPS and CBS. CONCLUSIONS: These findings explain the neuroanatomical basis of the overlapping presenting signs and symptoms of PSPS and CBS, in Hybrids.

Paraneoplastic and metastatic neurologic complications of Merkel cell carcinoma.

Merkel cell carcinoma is a rare primary cutaneous neuroendocrine tumor that is locally aggressive and frequently accompanied by distant metastases. Neurologic complications of Merkel cell carcinoma are rare. We describe a 69-year-old man who presented with Lambert-Eaton myasthenic syndrome and was found to have Merkel cell carcinoma. The paraneoplastic syndrome improved with initial treatment of the malignancy. He subsequently developed a solitary brain metastasis and died of leptomeningeal carcinomatosis.