[Neurogenic thoracic outlet syndrome]. / Neurogeen thoracic-outletsyndroom.

Neurogenic thoracic outlet syndrome (nTOS) is a type of thoracic outlet syndrome (TOS) where compression of the brachial plexus is responsible for development of upper-extremity, head and neck symptoms. We present a 16-year-old and a 34-year-old patient with nTOS. Diagnosis in both cases was done by following the recently published reporting standards for (n)TOS. After this multidisciplinary diagnostic work-up we performed a transaxillary thoracic outlet decompression (TOD). Due to lack of literature, difficult nomenclature and complexity of diagnosis and treatment, diagnosis of nTOS is often delayed. Recent experience shows that treatment of nTOS is safe and effective, both in the short term and the long term.

"On" state freezing of gait in Parkinson disease: a paradoxical levodopa-induced complication.

OBJECTIVE: To describe the phenotype of levodopa-induced "on" freezing of gait (FOG) in Parkinson disease (PD). METHODS: We present a diagnostic approach to separate "on" FOG (deterioration during the "on state") from other FOG forms. Four patients with PD with suspected "on" FOG were examined in the "off state" (>12 hours after last medication intake), "on state" (peak effect of usual medication), and "supra-on" state (after intake of at least twice the usual dose). RESULTS: Patients showed clear "on" FOG, which worsened in a dose-dependent fashion from the "on" to the "supra-on" state. Two patients also demonstrated FOG during the "off state," of lesser magnitude than during "on." In addition, levodopa produced motor blocks in hand and feet movements, while other parkinsonian features improved. None of the patients had cognitive impairment or a predating "off" FOG. CONCLUSIONS: True "on" FOG exists as a rare phenotype in PD, unassociated with cognitive impairment or a predating "off" FOG. Distinguishing the different FOG subtypes requires a comprehensive motor assessment in at least 3 medication states.

Imaging the impact of genes on Parkinson's disease.

Although Parkinson's disease (PD) has traditionally been considered to be a non-genetic disorder, recent progress in the neurogenetics of PD provided converging evidence that genetic factors play a relevant role in the etiology of PD. The strongest case for a genetic contribution to PD was made by the discovery of mutations in single genes that can cause autosomal dominant (alpha-synuclein (SNCA)) and leucine rich repeat kinase 2 (LRRK2) gene) or recessive (Parkin, PTEN-induced putative kinase 1 (PINK1), DJ-1, and ATP13A2 gene) forms of PD. Here, we review how structural and functional neuroimaging of individuals carrying a mutation in one of the PD genes has offered a unique avenue of research into the pathogenesis of PD. In symptomatic mutation carriers (i.e. those with overt disease), brain mapping can help to link the molecular pathogenesis of PD more directly with functional and structural changes in the intact human brain. In addition, neuroimaging of presymptomatic (i.e. non-manifesting) mutation carriers has emerged as a valuable tool to identify mechanisms of adaptive motor reorganization at the preclinical stage that may prevent or delay clinical manifestation. In addition to mutations causing monogenic forms of PD, common polymorphisms in genes that influence mono-aminergic signaling or synaptic plasticity may have modifying effects on distinct aspects of PD. We also discuss how functional and structural neuroimaging can be used to better characterize these genotype-phenotype correlations.

Heterozygous carriers of a Parkin or PINK1 mutation share a common functional endophenotype.

OBJECTIVE: To use a combined neurogenetic-neuroimaging approach to examine the functional consequences of preclinical dopaminergic nigrostriatal dysfunction in the human motor system. Specifically, we examined how a single heterozygous mutation in different genes associated with recessively inherited Parkinson disease alters the cortical control of sequential finger movements. METHODS: Nonmanifesting individuals carrying a single heterozygous Parkin (n = 13) or PINK1 (n = 9) mutation and 23 healthy controls without these mutations were studied with functional MRI (fMRI). During fMRI, participants performed simple sequences of three thumb-to-finger opposition movements with their right dominant hand. Since heterozygous Parkin and PINK1 mutations cause a latent dopaminergic nigrostriatal dysfunction, we predicted a compensatory recruitment of those rostral premotor areas that are normally implicated in the control of complex motor sequences. We expected this overactivity to be independent of the underlying genotype. RESULTS: Task performance was comparable for all groups. The performance of a simple motor sequence task consistently activated the rostral supplementary motor area and right rostral dorsal premotor cortex in mutation carriers but not in controls. Task-related activation of these premotor areas was similar in carriers of a Parkin or PINK1 mutation. CONCLUSION: Mutations in different genes linked to recessively inherited Parkinson disease are associated with an additional recruitment of rostral supplementary motor area and rostral dorsal premotor cortex during a simple motor sequence task. These premotor areas were recruited independently of the underlying genotype. The observed activation most likely reflects a "generic" compensatory mechanism to maintain motor function in the context of a mild dopaminergic deficit.

Spinal cord compression by an arachnoid cyst: a case report and review of the literature.

BACKGROUND: Intradural extramedullary cysts are a rare cause of spinal cord compression. We present a case with slowly progressive radicular pain and gait disorder over several years, due to medullary compression by a giant cervico-thoracic arachnoid cyst. CASE REPORT: A 65-year-old man presented with progressive pain irradiating from the lower back to the waist and both legs over a period of 2 years. Neurological examination revealed a decreased sensation for pain, vibration, and proprioception below T7, without muscle weakness. Reflexes were increased in both lower extremities, with bilateral extensor plantar responses. The MRI showed an intradural extramedullary lesion, suggestive for an arachnoid cyst. The spinal cord was displaced and compressed anteriorly, with a smallest diameter of 1 mm. Surgical resection of the cyst resulted in decompression and re-expansion of the spinal cord as visualized with MRI. Neurological examination 6 months after surgery revealed nearly complete recovery of neurological deficits. DISCUSSION: This case report, together with a review of the literature, shows the extreme adaptability of the human spinal cord, in cases of slowly progressive compression.