Eight-and-a-half syndrome: a rare presentation

Eight-and-a-half syndrome is a rare entity characterised by conjugate horizontal gaze palsy, ipsilateral internuclear ophthalmoplegia and ipsilateral lower motor neuron type facial palsy. It is due to a lesion affecting median longitudinal fasciculus, paramedian pontine reticular formation and facial nerve fascicle on the same side at the level of pons. The diagnosis is easily missed as it needs detailed ocular movement examination. It is mainly caused due to infarction or demyelinating conditions. We are reporting an interesting case of a 54-year-old man with right-side eight-and-a-half syndrome due to acute ischaemic stroke and ST-elevation myocardial infarction of the inferior wall.

Experimental study on the efficacy of a hybrid artificial nerve: The hot dog method

Introduction: We hypothesized that hybrid artificial nerves might overcome the limitations of a nerve conduit by isolating nerve fascicles from autologous nerves. Nerve sacrifice during harvest, a drawback of conventional autologous nerve transplantation, may be reduced by the hot dog method. The hot dog method (based on the morphology of hybrid artificial nerves) adds nerve conduits to autologous nerve fascicles. Methods: Forty-eight rats with a 10-mm sciatic nerve defect were divided into six groups ( n = 8 per group) according to the neural reconstruction method: autologous nerve transplantation, the hot dog method, nerve conduit, nerve fascicle transplantation, sham control, and nerve fascicle isolation were classified as Groups I, II, III, IV, V, and VI, respectively. The sciatic nerve function was assessed in these groups, a histological evaluation was performed, and statistical analyses were conducted based on these data. Results: Group III (nerve conduit) and Group IV (nerve fascicle transplantation) showed the lowest functional and axonal regenerative effects, followed by Group II (hot dog method) and Group I (autologous nerve transplantation). Group VI (nerve fascicle isolation) tended to achieve better recovery in motor function and axonal regeneration than Group I (autologous nerve transplantation). Conclusions: The hot dog method is simple, safe, and easy to execute. This method can serve as a new neural reconstruction method that uses artificial nerves.

Unraveling the mysteries of the midbrain – A case report

Context: The rostral midbrain and thalamomesencephalic junction are the supranuclear premotor control of vertical eye movements, and is supplied by the posterior thalamo-subthalamic paramedian artery originated from P1 segment of posterior cerebral artery. Case report: A 51-year-old man presented with sudden speech difficulties, dizziness and dyplopia, associated with moderate intensity headache. Neuroophthalmological examination revealed incomplete ptosis of the right eye, with mydriatic pupil, poorly reactive to light. No eye movements were present on attempted upward gaze. On attempted downward gaze, depression of the left eye was observed but with absent saccades. Lateral gaze to the right was intact, while attempted gaze deviation to the left revealed adduction deficit of the right eye with incomplete abduction of the left eye without nystagmus. Convergence was absent. He exhibited left hemiataxia with left hypoestesia. MRI showed acute right paramedian thalamic and mesencephalic stroke. Conclusions: About the vertical one and a half syndrome, it was suggested damage in the pathway to contralateral downgaze neurons before its decussation with the unilateral interstitial nucleus of Cajal. As for the contralateral lateral rectus palsy we infer that this patient’s abduction deficit was due to pseudo-abducens palsy, with several mechanisms that could explain abduction deficits associated with upgaze palsy. Claude’s syndrome is usually explained by a lesion of oculomotor nerve fascicle and the superior cerebellar peduncle, affecting cerebellothalamic connections.

A Linear Variant of Segmental Schwannomatosis Localized to the Upper Extremity

Introduction Schwannomas represent benign peripheral nerve sheath tumors. Their phenotypic presentations in schwannomatosis and segmental schwannomatosis have been well described. To date, however, cases of schwannomatosis or multiple schwannomas localized to a single nerve fascicle have been limited in the literature. Case Presentation In this study, we identify a case of a 48 year-old non-neurofibromatosis male who presented with symptomatic schwannomas localized to a single nerve fascicle of the upper extremity. Intraoperative exploration revealed four schwannomas arising from a 15-cm segment of ulnar nerve fascicle. Surgical excision was successful, without neurological deficit or recurrence. Conclusion This study identifies a case of schwannomatosis localized to a single nerve fascicle that may represent a linear variant of segmental schwannomatosis. The presentation may represent a temporary linear appearance in progression to “nonlinear” segmental variant; however, a molecularly distinct subset of schwannomas cannot be excluded.

Calving-related intradural avulsion injuries of the thoracolumbar spinal nerve roots in a calf

Calving difficulty may lead to traumatic peripheral nerve injury. A male, 8-mo-old, Japanese Black calf with a history of secondary dystocia as a result of fetal gigantism had lameness and gait disturbance. At autopsy, multifocal dural thickening with adhesions to the adjacent spinal cord was observed at T12–13 and L4–5 vertebral levels. Microscopically, numerous traumatic neuroma-like fascicles of nerve twigs were embedded in the dura mater with abundant collagenous connective tissue. By immunohistochemistry, axons and Schwann cells were confirmed in each nerve fascicle. Our observations suggest that avulsion injuries in the preganglionic fibers of the spinal nerve roots, and secondary spinal cord compression, resulted in the development of neurologic signs.

Role of High-Resolution Ultrasonography in Evaluation of Median Nerve and Thickness of Flexor Retinaculum in Patients with Hypothyroidism

Objectives: To determine the role of high resolution ultrasonography in evaluation of cross sectional area, maximum nerve fascicle thickness and thickness/width ratio of the median nerve and flexor retinaculum thickness in patients with hypothyroidism and to correlate it with the healthy volunteers. Material and Methods: A prospective study was conducted from February 2018 to October 2019 on 62 patients which included 32 clinically proven cases of hypothyroidism and 30 healthy volunteers. High resolution ultrasonography was performed using high frequency linear probes. Results: The most affected parameter was cross sectional area of median nerve at three levels, inlet/outlet ratio of CSA of the median nerve and thickness of flexor retinaculum in hypothyroidism patients in correlation with healthy volunteers. These parameters showed statistically significant p values. Maximum nerve fascicle thickness and thickness/width ratio of the median nerve showed no statistical significance in hypothyroid patients in correlation with healthy volunteers. Conclusion: High-resolution ultrasonography plays an important role in evaluating the changes occuring in cross sectional area of the median nerve, its inlet/outlet CSA ratio and flexor retinaculum thickness in hypothyroidism patients as correlated with the healthy volunteers.