Characterising effects of impact velocity on brain and behaviour in a model of diffuse traumatic axonal injury.

The velocity of impact between an object and the human head is a critical factor influencing brain injury outcomes but has not been explored in any detail in animal models. Here we provide a comprehensive overview of the interplay between impact velocity and injury severity in a well-established weight-drop impact acceleration (WDIA) model of diffuse brain injury in rodents. We modified the standard WDIA model to produce impact velocities of 5.4, 5.85 and 6.15 m/s while keeping constant the weight and the drop height. Gradations in impact velocity produced progressive degrees of injury severity measured behaviourally, electrophysiologically and anatomically, with the former two methods showing greater sensitivity to changes in impact velocity. There were impact velocity-dependent reductions in sensorimotor performance and in cortical depth-related depression of sensory cortex responses; however axonal injury (demonstrated by immunohistochemistry for ß-amyloid precursor protein and neurofilament heavy-chain) was discernible only at the highest impact velocity. We conclude that the WDIA model is capable of producing graded axonal injury in a repeatable manner, and as such will prove useful in the study of the biomechanics, pathophysiology and potential treatment of diffuse axonal injury.

Short-term outcome after resection of neurogenic heterotopic ossification around the hips and elbow following encephalitis.

Heterotopic ossification (HO) is a potential complication following brain or spinal cord injuries and diseases. Post-encephalitis HO is rare, and the number of affected joints is a prognostic predictor. A literature review revealed only a limited number of such cases, with one or two anatomical regions affected in each case. We report the case of a 21-year-old man who developed HO at the peri-articular regions of both hips and the right elbow post encephalitis. He had good functional outcome following excision of the ossific masses. There has not been any recurrence for up to two years from the first surgery. To the best of our knowledge, this is the first such case involving more than two anatomical regions, and the first reported case from Sri Lanka.

An unusual case of adult onset progressive heterotopic ossification suggesting a variant form of fibrodysplasia ossificans progressiva.

Progressive heterotopic ossification (HO) is a rare disease of genetic inheritance. Fibrodysplasia ossificans progressiva (FOP) is an identified debilitating subcategory in which anomalous ossification usually begins in childhood. Congenital big toe anomalies and specific patterns of progression of ossification confirm the classic disease. Adult onset disease is extremely rare. The mechanism of disease progression is still unclear, and there is no consensus on the treatment modalities. We report a 47-year-old man with adult-onset progressive HO around the bilateral pelvic and shoulder girdles and thoracolumbar spine, which suggested a variant form of FOP. Although surgical excision is considered counterproductive in FOP, our patient showed improvement in his shoulder movement following surgery. Other management strategies, including surgery around the hips, indomethacin prophylaxis, irradiation and bisphosphonate therapy, did not improve his range of movement or disease progression.

A rare cervical spine abnormality associated with neurofibromatosis.

Spinal abnormalities such as kyphoscoliosis and vertebral scalloping are frequent occurrences in type 1 neurofibromatosis (NF1). We report this rare case of posterior displacement of C3 vertebral body into the spinal canal causing severe cord compression associated with neurofibromatosis in a 13-year old girl. She underwent anterior excision of C3 vertebral body, bone graft and fixation of C2- C4, with improvement of her symptoms.