Susac's syndrome: clinical course and epidemiology in a Central European population.

OBJECTIVE: Susac's syndrome is characterized by inflammation and occlusion of pre-capillary arterioles with the clinical triad of branch retinal artery occlusion (BRAO), encephalopathy and hearing loss. No epidemiological data are available for the disease. METHODS: All neurology departments in Austria were addressed to report adult patients who were on immunosuppressive treatment for a diagnosis of Susac's syndrome between 1 August 2010 and 1 August 2015. Clinical course, treatment regimens, period and point prevalence rates, and annual incidence of Susac's syndrome in Austria in people over 19 years of age are reported. RESULTS: Ten patients with Susac's syndrome were identified, and eight of them were newly diagnosed within the five-year timeframe. Minimum five-year period prevalence of the disease is 0.148/100,000 (95% confidence interval (CI) 0.071-0.272), annual incidence is 0.024/100,000 (95% CI 0.010-0.047). Minimum point prevalence rates varied from 0.030/100,000 (95% CI 0.004-0.108) to 0.088/100,000 (95% CI 0.032-0.192). Of all 10 patients, 8 showed typical callosal or internal capsule magnetic resonance imaging lesions at first presentation, 7 presented with BRAO and 5 had hearing loss or tinnitus at the beginning of the disease. Four patients developed the complete clinical triad of Susac's syndrome during the observation period. CONCLUSIONS: We provide for the first time population-based data about the clinical course, prevalence and incidence of Susac's syndrome.

Mutation screen reveals novel variants and expands the phenotypes associated with DYNC1H1.

Dynein, cytoplasmic 1, heavy chain 1 (DYNC1H1) encodes a necessary subunit of the cytoplasmic dynein complex, which traffics cargo along microtubules. Dominant DYNC1H1 mutations are implicated in neural diseases, including spinal muscular atrophy with lower extremity dominance (SMA-LED), intellectual disability with neuronal migration defects, malformations of cortical development, and Charcot-Marie-Tooth disease, type 2O. We hypothesized that additional variants could be found in these and novel motoneuron and related diseases. Therefore, we analyzed our database of 1024 whole exome sequencing samples of motoneuron and related diseases for novel single nucleotide variations. We filtered these results for significant variants, which were further screened using segregation analysis in available family members. Analysis revealed six novel, rare, and highly conserved variants. Three of these are likely pathogenic and encompass a broad phenotypic spectrum with distinct disease clusters. Our findings suggest that DYNC1H1 variants can cause not only lower, but also upper motor neuron disease. It thus adds DYNC1H1 to the growing list of spastic paraplegia related genes in microtubule-dependent motor protein pathways.

Multimodality MRI and MRA for decision making in minor stroke: a case with internal carotid and distal middle cerebral artery occlusion.

We report the case of a 65-year-old man who presented with mild, rapidly improving stroke symptoms. Acute magnetic resonance imaging disclosed no diffusion abnormalities but a tandem internal carotid artery/distal middle cerebral artery occlusion associated with a large corresponding deficit on perfusion imaging. In addition, there was a cross-flow to the middle cerebral artery via the anterior communicating artery. Therefore, intravenous thrombolysis was initiated that led to rapid reopening of the middle cerebral artery and left the patient free of symptoms. Our observation highlights the possible benefit of systemic thrombolytic treatment even in the setting of an internal carotid artery occlusion and the substantial contribution of multimodal magnetic resonance imaging for a risk-benefit estimate.

Phenotypes of the N88S Berardinelli-Seip congenital lipodystrophy 2 mutation.

Recently, two missense mutations (N88S, S90L) in the Berardinelli-Seip congenital lipodystrophy gene have been identified in autosomal dominant distal hereditary motor neuropathy and Silver syndrome. We report the phenotypic consequences of the N88S mutation in 90 patients of 1 large Austrian family and two unrelated German families. Variation in the clinical and electrophysiological phenotype enabled us to distinguish six subtypes. In 4.4%, the disorder was not penetrant. Twenty percent of the patients were subclinically affected; some of these patients could only be detected by pathological nerve conduction studies. A distal hereditary motor neuropathy type V phenotype characterized by predominant hand muscle involvement was found in 31.1%, whereas 14.5% showed typical Silver syndrome with amyotrophy of the small hand muscles and spasticity of the lower extremities. Moreover, the phenotype present in 20% was compatible with Charcot-Marie-Tooth disease. In 10%, the clinical diagnosis of pure or complicated hereditary spastic paraparesis was made. Electrophysiological studies showed an axonal neuropathy but also chronodispersion of compound motor action potentials and conduction blocks. Sensory nerve conduction studies were rarely pathological. Our study indicates that the dominant N88S mutation in the Berardinelli-Seip congenital lipodystrophy gene 2 leads to a broad spectrum of motor neuron disorders.