Case report: a giant arachnoid cyst masking Alzheimer's disease

Arachnoid cyst presenting as a neurosurgical emergency: a case report

Introduction

Arachnoid cysts are intra-arachnoid lesions filled with cerebrospinal fluid. They account for ~1% of all intracranial mass lesions and are non-neoplastic collections of cerebrospinal fluid within an anomalous arachnoid enclosure.

Case presentation

The authors report a 35-year-old Arabian male who presented to the ER with a history of sudden loss of consciousness, anisocoria, and right hemiparesis. Contrast tomography showed a large frontoparietotemporal cyst (7.7×5.8×5.4) with uncal herniation and a midline shift of 12 mm. An emergency left FTP craniotomy with an excision of the cyst was performed.

Discussion

Arachnoid cysts can be categorized as primary or secondary, arising congenitally or due to factors like trauma, infection, or neoplasia. It can rupture, leading to internal bleeding, causing symptoms such as headaches, seizures, and neurological decline. Rapid diagnosis is vital, with cranial computed tomography scans preferred for emergencies. Treatment options include surgical intervention like craniotomy, fenestration, or cyst peritoneal shunts. For uncal herniation, surgery can be successful and results depends on the amount of herniation.

Conclusion

Although benign, the arachnoid cysts led to uncal herniation when they become 'tension' cysts. A high level of suspicion is crucial for early recognition of the condition. Timely intervention has shown positive recovery outcomes.

Chronic hematoma superimposed to a large frontotemporal arachnoid cyst: evidence against crowding of audioverbal memory

We report a patient with a chronic subdural/epidural hematoma superimposed to a large arachnoid cyst occupying the left frontotemporal region. Both were discovered accidentally because of a trigeminal neuralgia and concomitant subjective memory complaints. Patient's sudden selective audioverbal memory impairment probably links to a primary cortical tone deregulation and expressed through deficits of arousal-mediating structures subtly impacted by the hematoma's progression. This case illustrates that in early-onset asymmetrical brain damage (usually left), language, audioverbal memory in particular, should not always come to dominate intact hemisphere function. A severity-threshold may exist below which inter-hemispheric reorganization of audioverbal memory is unlikely.

Seizures and Postictal Psychosis in a Patient With Retrocerebellar Arachnoid Cyst: A Case Report

Retrocerebellar arachnoid cysts are uncommon intracranial tumors, especially rare in adults. Although asymptomatic in the majority of cases, they may cause a variety of symptoms including convulsions. The causal involvement of these cysts in postictal psychosis, however, remains a topic that is not well-explained in the literature.

An 85-year-old Asian man presented with recurrent episodes of convulsions for the last seven months along with preceding headaches and postictal psychotic symptoms. MRI of the head revealed a retrocerebellar arachnoid cyst. He was commenced on symptomatic pharmacological therapy after he refused surgical intervention and remained symptom-free till his discharge from the hospital before being eventually lost to follow-up.

This case report focuses on the rare occurrence of a retrocerebellar arachnoid cyst with seizures and postictal psychosis and illustrates the necessity of further case studies and research to identify and explore the potential causal relationship between arachnoid cysts and psychosis.

The efficacy of cystoperitoneal shunting for the surgical management of intracranial arachnoid cysts in the elderly: A systematic review of the literature

Background:

Intracranial arachnoid cysts (AC) are benign, cerebrospinal fluid filled spaces within the arachnoid layer of the meninges. Neurosurgical intervention in children and young adults has been extensively studied, but the optimal strategy in the elderly remains unclear. Therefore, we performed a single center retrospective study combined with a systematic review of the literature to compare cystoperitoneal (CP) shunting with other surgical approaches in the elderly cohort.

Methods:

Retrospective neurosurgical database search between January 2005 and December 2018, and systematic review of the literature using PRISMA guidelines were performed. Inclusion criteria: Age 60 years or older, radiological diagnosis of intracranial AC, neurosurgical intervention, and neuroradiological (NOG score)/clinical outcome (COG score). Data from both sources were pooled and statistically analyzed.

Results:

Our literature search yielded 12 studies (34 patients), which were pooled with our institutional data (13 patients). CP shunts (7 patients; 15%), cyst fenestration (28 patients; 60%) and cyst marsupialisation/resection (10 patients; 21%) were the commonest approaches. Average duration of follow-up was 23.6, 26.9, and 9.5 months for each approach, respectively. There was no statistically significant association between choice of surgical intervention and NOG score (P = 0.417), COG score (P = 0.601), or complication rate (P = 0.955). However, CP shunting had the lowest complication rate, with only one patient developing chronic subdural haematoma.

Conclusion:

CP shunting is a safe and effective surgical treatment strategy for ACs in the elderly. It has similar clinical and radiological outcomes but superior risk profile when compared with other approaches. We advocate CP shunting as first line neurosurgical intervention for the management of intracranial ACs in the elderly.

Cut it out or wait it out? Case series of middle fossa arachnoid cysts presenting with psychiatric symptoms and a discussion of the ethics of neurosurgical management

Arachnoid cysts have been linked to neuropsychiatric morbidity. We describe two patients presenting with dissociative and manic symptoms believed to be associated with middle fossa arachnoid cysts. They were managed medically and remitted eventually, but symptoms were resistant. We briefly review the literature to discuss mechanisms by which cysts could cause symptoms and consider whether neurosurgical management would be appropriate. Although neurosurgery can be considered, its role is currently limited by practical and ethical considerations.