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  • Author or Editor: Sudheesh Ramachandran x
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Mustafa Nadi, Sudheesh Ramachandran, Abir Islam, Joanne Forden, Gui Fang Guo and Rajiv Midha

OBJECTIVE

Supercharge end-to-side (SETS) transfer, also referred to as reverse end-to-side transfer, distal to severe nerve compression neuropathy or in-continuity nerve injury is gaining clinical popularity despite questions about its effectiveness. Here, the authors examined SETS distal to experimental neuroma in-continuity (NIC) injuries for efficacy in enhancing neuronal regeneration and functional outcome, and, for the first time, they definitively evaluated the degree of contribution of the native and donor motor neuron pools.

METHODS

This study was conducted in 2 phases. In phase I, rats (n = 35) were assigned to one of 5 groups for unilateral sciatic nerve surgeries: group 1, tibial NIC with distal peroneal-tibial SETS; group 2, tibial NIC without SETS; group 3, intact tibial and severed peroneal nerves; group 4, tibial transection with SETS; and group 5, severed tibial and peroneal nerves. Recovery was evaluated biweekly using electrophysiology and locomotion tasks. At the phase I end point, after retrograde labeling, the spinal cords were analyzed to assess the degree of neuronal regeneration. In phase II, 20 new animals underwent primary retrograde labeling of the tibial nerve, following which they were assigned to one of the following 3 groups: group 1, group 2, and group 4. Then, secondary retrograde labeling from the tibial nerve was performed at the study end point to quantify the native versus donor regenerated neuronal pool.

RESULTS

In phase I studies, a significantly increased neuronal regeneration in group 1 (SETS) compared with all other groups was observed, but with modest (nonsignificant) improvement in electrophysiological and behavioral outcomes. In phase II experiments, the authors discovered that secondary labeling in group 1 was predominantly contributed from the donor (peroneal) pool. Double-labeling counts were dramatically higher in group 2 than in group 1, suggestive of hampered regeneration from the native tibial motor neuron pool across the NIC segment in the presence of SETS.

CONCLUSIONS

SETS is indeed an effective strategy to enhance axonal regeneration, which is mainly contributed by the donor neuronal pool. Moreover, the presence of a distal SETS coaptation appears to negatively influence neuronal regeneration across the NIC segment. The clinical significance is that SETS should only employ synergistic donors, as the use of antagonistic donors can downgrade recovery.

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Bryan Renne, Stefan Rueckriegel, Sudheesh Ramachandran, Julia Radic, Paul Steinbok and Ash Singhal

Bobble-head doll syndrome (BHDS) is a rare pediatric movement disorder presenting with involuntary 2- to 3-Hz head movements. Common signs and symptoms also found on presentation include macrocephaly, ataxia, developmental delay, optic disc pallor or atrophy, hyperreflexia, tremor, obesity, endocrinopathy, visual disturbance or impairment, headache, and vomiting, among others. The syndrome is associated with suprasellar cysts, third ventricular cysts, or aqueductal obstruction, along with a few other less common conditions. The cause of involuntary head motions is not understood. Treatment is surgical. The authors present 2 cases of BHDS. The first is a 14-year-old boy with BHDS associated with aqueductal obstruction and triventricular hydrocephalus secondary to a tectal tumor. He was successfully treated by endoscopic third ventriculostomy, and all symptoms resolved immediately in the recovery room. This case is unusual in its late age of symptom onset, the primacy of lateral (“no-no”) involuntary head rotations, and the associated tectal tumor. The second case is a 7.5-year-old girl with BHDS associated with a suprasellar cyst. She was successfully treated with an endoscopic fenestration but preexisting endocrinopathy persisted, and the patient was diagnosed with autism spectrum disorder at age 12 years. This second case is more typical of BHDS. A comprehensive and up-to-date review of the literature of BHDS and video documentation of the phenomenon are presented.