Sports-related concussion is a change in brain function following a direct or an indirect force to the head, identified in awake individuals and accounting for a considerable proportion of mild traumatic brain injury. Although the neurological signs and symptoms of concussion can be subtle and transient, there can be persistent sequelae, such as impaired attention and balance, that make affected patients particularly vulnerable to further injury. Currently, there is no accepted definition or diagnostic criteria for concussion, and there is no single assessment that is accepted as capable of identifying all patients with concussion. In this paper, the authors review the available screening tools for concussion, with particular emphasis on the role of visual function testing. In particular, they discuss the oculomotor assessment tools that are being investigated in the setting of concussion screening.
Eric S. Sussman, Allen L. Ho, Arjun V. Pendharkar and Jamshid Ghajar
Raphael Guzman, Arjun V. Pendharkar, Michel Zerah and Christian Sainte-Rose
Endoscopic third ventriculostomy (ETV) has become the procedure of choice for treatment of obstructive hydrocephalus. While patient selection is the most critical factor in determining the success of an ETV procedure, the technical challenge lies in the proper site of fenestration and the successful creation of a patent stoma. Positioning of a single balloon catheter at the level or below the floor of the third ventricle to achieve an optimal ventriculostomy can at times be challenging. Here, the authors describe the use of a double-barrel balloon catheter (NeuroBalloon catheter), which facilitates positioning across, as well as dilation of, the floor of the third ventricle. The surgical technique and nuances of using the NeuroBalloon catheter and the experience in more than 1000 cases are described. The occurrence of vascular injury was less than 0.1%, and the risk of balloon rupture was less than 2%. The authors found that the placement and deployment of this balloon catheter facilitate the creation of an adequate ventriculostomy in a few simple steps.
Arjun V. Pendharkar, Sabrina L. Levy, Allen L. Ho, Eric S. Sussman, Michelle Y. Cheng and Gary K. Steinberg
Stroke is one of the leading contributors to morbidity, mortality, and health care costs in the United States. Although several preclinical strategies have shown promise in the laboratory, few have succeeded in the clinical setting. Optogenetics represents a promising molecular tool, which enables highly specific circuit-level neuromodulation. Here, the conceptual background and preclinical body of evidence for optogenetics are reviewed, and translational considerations in stroke recovery are discussed.
Rohaid Ali, Ian D. Connolly, Amy Li, Omar A. Choudhri, Arjun V. Pendharkar and Gary K. Steinberg
From February 4 to 11, 1945, President Franklin D. Roosevelt of the United States, Soviet Union Premier Joseph Stalin, and British Prime Minister Winston Churchill met near Yalta in Crimea to discuss how post–World War II (WWII) Europe should be organized. Within 2 decades of this conference, all 3 men had died. President Roosevelt died 2 months after the Yalta Conference due to a hemorrhagic stroke. Premier Stalin died 8 years later, also due to a hemorrhagic stroke. Finally, Prime Minister Churchill died 20 years after the conference because of complications due to stroke. At the time of Yalta, these 3 men were the leaders of the most powerful countries in the world. The subsequent deterioration of their health and eventual death had varying degrees of historical significance. Churchill's illness forced him to resign as British prime minister, and the events that unfolded immediately after his resignation included Britain's mismanagement of the Egyptian Suez Crisis and also a period of mistrust with the United States. Furthermore, Roosevelt was still president and Stalin was still premier at their times of passing, so their deaths carried huge political ramifications not only for their respective countries but also for international relations. The early death of Roosevelt, in particular, may have exacerbated post-WWII miscommunication between America and the Soviet Union—miscommunication that may have helped precipitate the Cold War.
Arjun V. Pendharkar, Eric S. Sussman, Allen L. Ho, Melanie G. Hayden Gephart and Laurence Katznelson
Cushing's disease (CD) is a state of excess glucocorticoid production resulting from an adrenocorticotropic hormone (ACTH)–secreting pituitary adenoma. The gold-standard treatment for CD is transsphenoidal adenomectomy. In the hands of an experienced neurosurgeon, gross-total resection is possible in the majority of ACTH-secreting pituitary adenomas, with early postoperative remission rates ranging from 67% to 95%. In contrast to the strong data in support of resection, the clinical course of postsurgical persistent or recurrent disease remains unclear. There is significant variability in recurrence rates, with reports as high as 36% with a mean time to recurrence of 15–50 months. It is therefore important to develop biochemical criteria that define postsurgical remission and that may provide prognosis for long-term recurrence. Despite the use of a number of biochemical assessments, there is debate regarding the accuracy of these tests in predicting recurrence. Here, the authors review the various biochemical criteria and assess their utility in predicting CD recurrence after resection.
Allen L. Ho, Elizabeth Erickson-Direnzo, Arjun V. Pendharkar, Chih-Kwang Sung and Casey H. Halpern
Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors’ knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach.
Robert H. Andres, Arjun V. Pendharkar, Dominique Kuhlen and Luigi Mariani
Patients requiring CSF shunts frequently have comorbidities that can influence water and electrolyte balances. The authors report on a case involving a ventriculoperitoneal shunt in a patient who underwent intravenous hyperhydration and withdrawal of vasopressin substitution prior to scheduled high-dose chemotherapy regimen for a metastatic suprasellar germinoma. After acute neurological deterioration, the patient underwent CT scanning that demonstrated ventriculomegaly. A shunt tap revealed no flow and negative opening pressure. Due to suspicion of proximal shunt malfunction, the comatose patient underwent immediate surgical exploration of the ventricle catheter, which was found to be patent. However, acute severe hypernatremia was diagnosed during the procedure. After correction of the electrolyte disturbances, the patient regained consciousness and made a good recovery. Although rare, the effects of acute severe hypernatremia on brain volume and ventricular size should be considered in the differential diagnosis of ventriculoperitoneal shunt failure.
Arjun Vivek Pendharkar, Maryam Nour Shahin, Allen Lin Ho, Eric Scott Sussman, David Arnold Purger, Anand Veeravagu, John Kevin Ratliff and Atman Mukesh Desai
Spine surgery is a key target for cost reduction within the United States health care system. One possible strategy involves the transition of inpatient surgeries to the ambulatory setting. Lumbar laminectomy with or without discectomy, lumbar fusion, anterior cervical discectomy and fusion, and cervical disc arthroplasty all represent promising candidates for outpatient surgeries in select populations. In this focused review, the authors clarify the different definitions used in studies describing outpatient spine surgery. They also discuss the body of evidence supporting each of these procedures and summarize the proposed cost savings. Finally, they examine several patient- and surgeon-specific considerations to highlight the barriers in translating outpatient spine surgery into actual practice.
Allen L. Ho, Anne-Mary N. Salib, Arjun V. Pendharkar, Eric S. Sussman, William J. Giardino and Casey H. Halpern
Alcohol use disorder (AUD) is a difficult to treat condition with a significant global public health and cost burden. The nucleus accumbens (NAc) has been implicated in AUD and identified as an ideal target for deep brain stimulation (DBS). There are promising preclinical animal studies of DBS for alcohol consumption as well as some initial human clinical studies that have shown some promise at reducing alcohol-related cravings and, in some instances, achieving long-term abstinence. In this review, the authors discuss the evidence and concepts supporting the role of the NAc in AUD, summarize the findings from published NAc DBS studies in animal models and humans, and consider the challenges and propose future directions for neuromodulation of the NAc for the treatment of AUD.
Allen L. Ho, Eric S. Sussman, Arjun V. Pendharkar, Dan E. Azagury, Cara Bohon and Casey H. Halpern
Obesity is one of the most serious public health concerns in the US. While bariatric surgery has been shown to be successful for treatment of morbid obesity for those who have undergone unsuccessful behavioral modification, its associated risks and rates of relapse are not insignificant. There exists a neurological basis for the binge-like feeding behavior observed in morbid obesity that is believed to be due to dysregulation of the reward circuitry. The authors present a review of the evidence of the neuroanatomical basis for obesity, the potential neural targets for deep brain stimulation (DBS), as well as a rationale for DBS and future trial design. Identification of an appropriate patient population that would most likely benefit from this type of therapy is essential. There are also significant cost and ethical considerations for such a neuromodulatory intervention designed to alter maladaptive behavior. Finally, the authors present a consolidated set of inclusion criteria and study end points that should serve as the basis for any trial of DBS for obesity.