Search Results

You are looking at 21 - 30 of 60 items for

  • Author or Editor: Alan R. Cohen x
Clear All Modify Search
Restricted access

Timothy W. Vogel, Biji Bahuleyan, Shenandoah Robinson and Alan R. Cohen

Object

Hydrocephalus remains a major public health problem. Conventional treatment has relied on extracranial shunting of CSF to another systemic site, but this approach is associated with a high rate of complications. Endoscopic third ventriculostomy (ETV) is a novel treatment for select forms of hydrocephalus that can eliminate the need for implantation of a lifelong ventricular shunt system. However, the indications for ETV are contested and its long-term effectiveness is not well established.

Methods

The authors selected 100 consecutive patients who underwent ETV for hydrocephalus beginning in 1994. Patients were enrolled and treated at a single institution by a single surgeon. The primary outcome was success of ETV, with success defined as no need for subsequent surgery for hydrocephalus.

Results

Ninety-five patients satisfied the inclusion criteria. The mean follow-up period was 5.1 years (median 4.7 years) with follow-up data available for as long as 17 years. Patients commonly presented with headache (85%), ataxia (34%), emesis (29%), and changes in vision (27%). The success rate for ETV was 75%. Twenty-one patients (22%) in the series had malfunctioning shunts preoperatively and 13 (62%) were successfully treated with ETV. Preoperative inferior bowing of the third ventricle floor on MRI was significantly associated with ETV success (p < 0.05).

Conclusions

Endoscopic third ventriculostomy is an effective and durable treatment for select patients with hydrocephalus. When successful, the procedure eliminates the lifelong complications associated with implanted ventricular shunts.

Restricted access

Osmond C. Wu, Sunil Manjila, Nima Malakooti and Alan R. Cohen

Among the families that have influenced the development of modern medicine into what it is today, the Monro lineage stands as one of the most notable. Alexander Monro primus (1697–1767) was the first of 3 generations with the same name, a dynasty that spanned 126 years occupying the Chair of Anatomy one after the other at the University of Edinburgh. After becoming Professor of Anatomy at the University of Edinburgh in 1719, Monro primus played a principal role in the establishment of the University of Edinburgh School of Medicine and the Edinburgh Royal Infirmary. In 1726, he published The Anatomy of the Humane Bones, of which 8 editions were printed during his lifetime. His son, Alexander Monro secundus (1733–1817), arguably the most notable of the 3 men, succeeded him as Professor of Anatomy. A highly regarded lecturer and anatomist, Monro secundus studied under many great physicians, including William Hunter and Johann Friedrich Meckel the Elder, and was also teacher to other well-known figures at the time, such as Joseph Black and Thomas Trotter. His most notable contributions include his work with the lymphatic system, the interventricular foramen (of Monro), and the Monro-Kellie doctrine. Alexander Monro tertius (1773–1859), the last of the dynasty, also succeeded his father as Professor of Anatomy. His work included insights into abdominal aortic aneurysms and the anatomy of the genitourinary system. The prominent association of the Monro family with the University of Edinburgh and the effects of a tenured professorship under the concept of “Ad vitam aut culpam” over successive generations are also described. To the best of the authors' knowledge, this historical review of the Monro family is among the few published in neurosurgical literature. A vivid historical overview of the medical contributions of the most famous and influential dynasty of physicians in Edinburgh at that time is provided, with relevant excerpts from original publications.

Restricted access

Alan R. Cohen, Jeffrey H. Wisoff, Jeffrey C. Allen and Fred Epstein

✓ The authors review their experience with the operative management of 19 consecutive cases of malignant astrocytoma of the spinal cord. There was a male to female ratio of 1.1:1, and the median age of the population was 14 years (range 1 to 32 years). The median duration of symptoms prior to definitive diagnosis was 7 weeks. Radical excision was carried out in all cases, with 18 patients (95%) receiving radiotherapy and 10 patients (53%) receiving chemotherapy as well.

To date, 15 (79%) of the 19 patients in this series have died, with a median survival period of 6 months following surgery. No patient improved after operation. Hydrocephalus was present in 11 patients (58%), seven of whom underwent ventricular shunting procedures. Dissemination of disease was found in 11 patients (58%). Extraneural metastases did not occur in the absence of a ventricular shunt. The authors conclude that malignant astrocytomas of the spinal cord are heralded by a short history followed by rapid neurological deterioration and usually death. The rationale for operation is discussed, and an aggressive approach utilizing adjuvant therapy directed at the entire neuraxis is suggested.

Restricted access

Alan R. Cohen, Timothy W. Vogel and Hart G. W. Lidov

The authors describe an 8-year-old girl who underwent emergency posterior fossa surgery for resection of a large cerebellar astrocytoma in November 1939. The surgery was carried out by Franc D. Ingraham at Boston Children's Hospital a decade after he established the first pediatric neurosurgical service in the world at the same institution. Four years later the tumor recurred and the patient underwent repeat resection followed by external-beam radiation therapy. The pathological diagnosis by Sidney Farber was fibrillary astrocytoma.

The young girl is currently a healthy, functional 82-year-old woman. The authors believe that this 74-year follow-up represents one of the longest in history, if not the longest, of a patient undergoing resection of a brain tumor. A recent MRI study shows postoperative changes with no evidence of residual or recurrent tumor. The original block tissue specimen had been preserved. It was restained and examined, revealing the pathological diagnosis to be juvenile pilocytic astrocytoma.

The case is analyzed in the context of Ingraham's powerful and lasting impact on the field of pediatric neurosurgery.

Restricted access

Editorial

Imitation, immaturity, and injury

Ann-Christine Duhaime

Free access

Douglas L. Brockmeyer, Andrew Jea, Alan R. Cohen and Arnold H. Menezes

Restricted access

Carl B. Heilman, Eddie S. Kwan, Richard P. Klucznik and Alan R. Cohen

✓ Cirsoid aneurysms of the scalp are notoriously difficult lesions to manage. The authors report a patient in whom a large traumatic cirsoid aneurysm of the scalp was eliminated using a combined neurosurgical and interventional neuroradiological approach. Transarterial embolization was utilized to reduce arterial blood supply to the fistula. Thrombogenic Gianturco spring coils were then introduced via direct percutaneous puncture of the aneurysm. The aneurysm thrombosed and the multiple tortuous scalp vessels disappeared. One month after embolization, a small area of skin necrosis over the aneurysm necessitated surgical excision of the lesion. The thrombosed aneurysm was easily resected with minimal blood loss. Percutaneous embolization with thrombogenic coils in this case was a safe and effective ablative technique.

Full access

Harvey Chim, Sunil Manjila, Alan R. Cohen and Arun K. Gosain

The interplay of signals between dura mater, suture mesenchyme, and brain is essential in determining the fate of cranial sutures and the pathogenesis of premature suture fusion leading to craniosynostosis. At the forefront of research into suture fusion is the role of fibroblast growth factor and transforming growth factor–β, which have been found to be critical in the cell-signaling cascade involved in aberrant suture fusion. In this review, the authors discuss recent and ongoing research into the role of fibroblast growth factor and transforming growth factor–β in the etiopathogenesis of craniosynostosis.

Full access

Efrem M. Cox, Kathleen E. Knudson, Sunil Manjila and Alan R. Cohen

The authors present the first report of spinal congenital dermal sinus with paramedian dual ostia leading to 2 intradural epidermoid cysts. This 7-year-old girl had a history of recurrent left paramedian lumbosacral subcutaneous abscesses, with no chemical or pyogenic meningitis. Admission MRI studies demonstrated bilateral lumbar dermal sinus tracts and a tethered spinal cord. At surgery to release the tethered spinal cord the authors encountered paramedian dermal sinus tracts with dual ostia, as well as 2 intradural epidermoid cysts that were not readily apparent on MRI studies. Congenital dermal sinus should be considered in the differential diagnosis of lumbar subcutaneous abscesses, even if the neurocutaneous signatures are located off the midline.

Restricted access

Biji Bahuleyan, Sunil Manjila, Shenandoah Robinson and Alan R. Cohen

Object

Surgery for medically intractable epilepsy secondary to unihemispheric pathology has evolved from more aggressive hemispherectomy to less aggressive variations of hemispherotomy. The authors propose a novel minimally invasive endoscopic hemispherotomy that should give results comparable to conventional open craniotomy and microsurgery.

Methods

Endoscopic transventricular hemispherotomy was performed in 5 silicon-injected cadaveric heads in the authors' minimally invasive neurosurgery laboratory. The lateral ventricle was accessed endoscopically through a frontal and occipital bur hole. White matter disconnections were performed to unroof the temporal horn and to disconnect the frontobasal region, corpus callosum, and fornix.

Results

Using an endoscopic transventricular approach, all white matter disconnections were successfully performed in all 5 cadavers.

Conclusions

The authors have demonstrated the feasibility of endoscopic transventricular hemispherotomy in a cadaveric model. The technique is simple and could be useful in a subgroup of patients with parenchymal volume loss and ventriculomegaly.