Bilateral trochlear nerve palsy subsequent to ventriculoperitoneal shunting of normal pressure hydrocephalus

Systemic Review: Neurological Deficits following Ventriculoperitoneal Shunt (VPS) Insertion

A reduction in fluid absorption or an obstruction of normal outflow is a common cause of hydrocephalus. It typically requires medical attention, which frequently entails the placement of a ventriculoperitoneal shunt (VPS) to lower intracranial pressure. We intend to list the few, documented examples of neurological impairments resulting from the installation of a VPS in this systematic study. Two search engines (PubMed and Cochrane) were used to conduct a systematic review from 1975 to December 12, 2021. The following search terms were employed: neurological deficits or neurological injury or palsies or thalamus or tract or longitudinal fasciculus or somatotropy or fasciculus or hearing loss or hemisensory or cortico AND ventriculoperitoneal shunt or VPS AND hydrocephalus. The inclusion criteria included VPS, neurological deficits, and human participants. The exclusion criteria included ventriculoarterial shunt, lumboperitoneal shunt, nonhuman subjects, and infection. Twenty trials in total, including a total of 25 patients, were included. There were 17 case report studies. A total of 35/785 patients (4.46%) experienced neurological impairments. In 9/25 (36%) of shunt cases had one of the three recognized causes: trapped fourth ventricle, dandy walker, or syringomyelia. Most of the patients developed VI, VII nerve palsies 11/25 (44%) followed by weakness, cerebellar symptoms, and VI nerve palsy. The brainstem was seen to be the most often injured structure (15/25; 60%), followed by deep brain structures (thalamus, basal ganglia, and white matter tracts; 20%). Even though ventriculoperitoneal shunting is a routine and straightforward treatment, issues can still arise. Although rare, there have been reports of cranial nerve impairments, therefore care should be taken.

Brainstem herniation into the internal acoustic canal secondary to hydrocephalus in context of spontaneous cerebrospinal fluid otorrhea: report of a novel entity

INTRODUCTION AND CLINICAL PRESENTATION

The authors report a case of a 5-year-old boy presenting with vision loss, right-sided hearing loss, and facial paralysis secondary to hydrocephalus causing brainstem herniation into the internal auditory canal (IAC) following cerebrospinal fluid (CSF) otorrhea.

MANAGEMENT AND OUTCOME

After placement of a ventriculo-peritoneal shunt (VP shunt), the vision and facial palsy improved whilst hearing loss persisted. Imaging demonstrated partial reduction of the herniated brainstem and resolution of hydrocephalus. To our knowledge, this is the first case reported of brainstem herniation into the internal auditory canal.

Cranial nerve palsy secondary to cerebrospinal fluid diversion

OBJECTIVE

Cranial nerve palsy (CNP) secondary to cerebrospinal fluid (CSF) diversion is less familiar to us as a result of its rarity in incidence and insidiousness in presentation. This study aims to further expound the pathophysiological mechanism, clinical presentation, diagnosis, management and prognosis of CNP.

METHODS

From June 2012 to February 2015, 5 of 347 consecutive patients with CNPs secondary to different CSF diversion procedures were treated at our institution. A systematic PubMed search of published studies written in English for patients developing CNPs after CSF diversion procedures from January 1950 to June 2015 was conducted.

RESULTS

Overall, 29 studies and 5 patients of the current series totaling 53 CNPs met the inclusion criteria. CN II, III, IV, V, VI, VII and VIII were got involved in 2 (3.8%), 2 (3.8%), 5 (9.4%), 1 (1.9%), 44 (83.0%), 4 (7.5%) and 1 (1.9%) patients respectively. Thirty-eight patients (71.7%) developed CNPs following inadvertent lumbar puncture, 8 (15.1%) following lumbar drainage, and 7 (13.2%) following ventriculoperitoneal shunt. Forty-eight (90.6%) patients got resolved completely.

CONCLUSIONS

The proposed mechanism of CNP after CSF diversion procedure is CSF hypovolemia and subsequent downward displacement of the brain and traction and distortion of the vascular and peripheral neural structures. As a result of its distinct anatomic characteristics rather than long intracranial course, CN VI is most commonly affected. With early recognition and timely conservative management, most patients could get favorable recovery.