The Management of Locally Invasive Primary Thyroid Paraganglioma: A Case Report and Review of the Literature.

Paragangliomas (PG) are very rare neuroendocrine tumours, arising from neural crest derived paraganglia of the autonomic nervous system. Primary thyroid paraganglioma (PTPG) is a rare site of PG and only 45 cases have been previously reported. The preoperative diagnosis of PTPGs presents a challenge as the clinical, cytological and histological features overlap with more common primary thyroid cancers. A 55 year old male was found to have significant enlargement of the left lobe of his thyroid. Following lobectomy, the thyroid lobe showed unencapsulated tumour which was positive for synaptophysin, CD56 and S100 (sustentacular cells). Post-operative imaging demonstrated incomplete resection. There was no post-operative radiotherapy and monitoring was by 6-12 monthly MRI. 48 months after his surgery he is alive and well with no evidence of disease progression. The diagnosis of PTPG was only made postoperatively, and although rare should be considered in the differential diagnosis of a hypervascular thyroid nodule.

Decreased levels of BAG3 in a family with a rare variant and in idiopathic dilated cardiomyopathy.

The most common cause of dilated cardiomyopathy and heart failure (HF) is ischemic heart disease; however, in a third of all patients the cause remains undefined and patients are diagnosed as having idiopathic dilated cardiomyopathy (IDC). Recent studies suggest that many patients with IDC have a family history of HF and rare genetic variants in over 35 genes have been shown to be causative of disease. We employed whole-exome sequencing to identify the causative variant in a large family with autosomal dominant transmission of dilated cardiomyopathy. Sequencing and subsequent informatics revealed a novel 10-nucleotide deletion in the BCL2-associated athanogene 3 (BAG3) gene (Ch10:del 121436332_12143641: del. 1266_1275 [NM 004281]) that segregated with all affected individuals. The deletion predicted a shift in the reading frame with the resultant deletion of 135 amino acids from the C-terminal end of the protein. Consistent with genetic variants in genes encoding other sarcomeric proteins there was a considerable amount of genetic heterogeneity in the affected family members. Interestingly, we also found that the levels of BAG3 protein were significantly reduced in the hearts from unrelated patients with end-stage HF undergoing cardiac transplantation when compared with non-failing controls. Diminished levels of BAG3 protein may be associated with both familial and non-familial forms of dilated cardiomyopathy.

Optochiasmal avulsion secondary to minor occipital trauma.

BACKGROUND: Optic nerve avulsion is an extremely rare occurrence and usually arises in the setting of severe fronto-orbital fractures or penetrating orbital injuries. However, a few cases have been associated with minor injury. OBJECTIVE: To overview the pathophysiology of delayed optochiasmal avulsion following minor ocipital trauma and discuss management options. METHODS: Report of a unique case of a 79-year-old woman who presented with delayed partial expulsion of the right globe and complete optic nerve avulsion following closed head injury to the occiput. CONCLUSION: Antero-posterior distortion of the skull following such a deceleration injury can cause laceration and thrombosis of the pre-chiasmal and pial arteries supplying the optic chiasm. The ensuing ischaemic changes subsequently caused delayed softening of the chiasm and its avulsion. The concomitant retrobulbar haemorrhage and mass effect within the orbit consequently led to the partial expulsion of the globe.

Supranormal stimulation of D1 dopamine receptors in the rodent prefrontal cortex impairs spatial working memory performance.

Although previous research has emphasized the beneficial effects of dopamine (DA) on functions of the prefrontal cortex (PFC), recent studies of animals exposed to mild stress indicate that excessive DA receptor stimulation may be detrimental to the spatial working memory functions of the PFC (Arnsten and Goldman-Rakic, 1990; Murphy et al., 1994, 1996a,b, 1997). In particular, these studies have suggested that supranormal stimulation of D1 receptors may contribute to the detrimental actions of DA in the PFC (Murphy et al., 1994, 1996a). The current study directly tested this hypothesis by examining the effects of infusing a full D1 receptor agonist, SKF 81297, into the PFC of rats performing a spatial working memory task, delayed alternation. SKF 81297 produced a dose-related impairment in delayed-alternation performance. The impairment was reversed by pretreatment with a D1 receptor antagonist, SCH 23390, consistent with drug actions at D1 receptors. SCH 23390 by itself had no effect on performance, although slightly higher doses impaired performance (Murphy et al., 1994, 1996a). There was a significant relationship between infusion location and drug efficacy; animals with cannulae anterior to the PFC were not impaired by SKF 81297 infusions. Taken together, these results demonstrate that supranormal D1 receptor stimulation in the PFC is sufficient to impair PFC working memory function. These cognitive data are consistent with recent electrophysiological studies of D1 receptor mechanisms affecting the PFC (Williams and Goldman-Rakic, 1995; Yang and Seamans, 1996). Increased D1 receptor stimulation during stress may serve to take the PFC "off-line" to allow posterior cortical and subcortical structures to regulate behavior, but may contribute to the vulnerability of the PFC in many neuropsychiatric disorders.