Naveed Kamal

Potential Uses of Isolated Toxin Peptides in Neuropathic Pain Relief: A Literature Review

Neuropathic pain is a subset of chronic pain that is caused by neurons that are damaged or firing aberrantly in the peripheral or central nervous systems. The treatment guidelines for neuropathic pain include antidepressants, calcium channel α2 delta ligands, topical therapy, and opioids as a second-line option. Pharmacotherapy has not been effective in the treatment of neuropathic pain except in the treatment of trigeminal neuralgia with carbamazepine. The inability to properly treat neuropathic pain causes frustration in both the patients and their treating physicians. Venoms, which are classically believed to be causes of pain and death, have peptide components that have been implicated in pain relief. Although some venoms are efficacious and have shown benefits in patients, their side-effect profile precludes their more widespread use. This review identifies and explores the use of venoms in neuropathic pain relief. This treatment can open doors to potential therapeutic targets. We believe that further research into the mechanisms of action of these receptors as well as their functions in nature will provide alternative therapies as well as a window into how they affect neuropathic pain.

Mechanical thrombectomy – is time still brain? The DAWN of a new era

Abstract Purpose: The purpose of this study is to review the history of treatments for acute ischemic stroke, examine developments in endovascular therapy, and discuss the future of the management of acute ischemic stroke. Methods: A selective review of recent clinical trials for the treatment of acute ischemic stroke was conducted. Results: We reviewed completed trials of the management of acute ischemic stroke including intravenous thrombolytics, intraarterial thrombolytics, and thrombectomy. We also assessed the future direction of research by reviewing ongoing clinical trials. Conclusions: The advancement of endovascular treatment for stroke has led to improved morbidity and mortality for patients. Future challenges include delivering these treatments to stroke centers worldwide.

Updates in the Management of Cerebral Infarctions and Subarachnoid Hemorrhage Secondary to Intracranial Arterial Dissection: A Systematic Review

OBJECTIVE Intracranial arterial dissection (IAD) is a rare cerebrovascular disease that is likely underdiagnosed because of the inherent difficulty of visualizing the subtle radiographic signs of the pathologic small intracranial arteries. No widespread consensus exists on the treatment of IAD, and thus it is often managed empirically because of the absence of major randomized controlled trials. In this study, we conducted a systematic review to evaluate the management and treatment options for IAD. METHODS We performed a systematic review in accordance with the PRISMA guidelines using the following databases: MEDLINE (PubMed) and Cochrane Library. Included studies were limited to human patients with dissections in intracranial vessels only. RESULTS A total of 82 studies were included in this systematic review. The most common complications of IAD were cerebral infarction and subarachnoid hemorrhage, and thus, patients with IAD can be subdivided into those presenting with either ischemia or hemorrhage, respectively. Those with ischemia were predominantly managed with antiplatelet therapy, whereas patients presenting with hemorrhage often were amenable to treatment with endovascular techniques. CONCLUSIONS Given these findings, clinicians should prescribe antiplatelet therapy for patients with IAD presenting with ischemia and consider endovascular treatment for those presenting with hemorrhage. However, further investigation is required given the heterogeneity of methods and reporting outcomes in the investigated studies.

The Role of Fast Imaging Employing Steady-State Acquisition (FIESTA) Magnetic Resonance Imaging for Assessment of Delayed Enhancement of Fat Graft Packing on Postoperative Imaging After Vestibular Schwannoma Surgery

OBJECTIVE To investigate the role and efficacy of fast imaging employing steady-state acquisition (FIESTA) imaging in distinguishing fat graft enhancement from residual or recurrent tumor after vestibular schwannoma (VS) surgery. METHODS A retrospective study of 33 patients who underwent VS resection via the retrosigmoid or translabyrinthine approach with fat graft reconstruction was performed. Magnetic resonance imaging (MRI) was collected at different time points: preoperative, immediate postoperative (24-48 hours), delayed postoperative (3-6 months after surgery), and yearly postoperative. The image sets contained T1, T2, fat-suppressed T1-weighted with gadolinium, and FIESTA. The radiographs were analyzed for tumor recurrence by the primary neurosurgeon and an independent blinded neuroradiologist. If fat-suppressed T1-weighted images demonstrated postoperative enhancement in the resection bed, a comparison was made with FIESTA imaging. RESULTS At 3-6 months postoperatively and at 1 year and beyond, 28 (84.8%) and 33 (100%) of patients, respectively, displayed delayed enhancement of the fat graft on postgadolinium fat-suppressed T1-weighted MRI. The enhancement seen on postgadolinium, fat-suppressed, T1-weighted MRI consistently correlated with the characteristic fat graft signal on FIESTA imaging and not tumor recurrence. FIESTA imaging was able to distinguish residual tumor from enhancing fat graft compared with postgadolinium, fat-suppressed, T1-weighted MRI (P < 0.0001) due to distinctive signaling patterns. CONCLUSIONS FIESTA is an effective tool in discerning fat graft enhancement from residual or recurrent tumor on delayed postoperative imaging after VS resection. Fat graft used in reconstruction consistently enhances on delayed postoperative postgadolinium, fat-suppressed, T1-weighted imaging, which correlates with the fat graft signal seen on FIESTA images.

Post-Traumatic Pituitary Tumor Apoplexy After Closed Head Injury: Case Report and Review of the Literature

BACKGROUND Head trauma is a rare inciting factor of pituitary apoplexy (PA); however, there is a clear temporal relationship between trauma and apoplexy, and this is the first reported case of PA after an assault. CASE DESCRIPTION We present a rare case of a 63-year-old man who developed PA after sustaining a closed head injury from assault with a metal pole. The patient had a known pituitary tumor for which he had previously declined surgical resection. On initial computed tomography scan, there was no traumatic intracerebral hemorrhage or subarachnoid hemorrhage. There was sellar expansion but no obvious sellar hemorrhage. Within 48 hours of admission, the patient was presumed septic after developing altered mental status, fevers, hypotension, and tachycardia. Magnetic resonance imaging of the brain with and without gadolinium revealed a poorly enhancing, necrotic, and hemorrhagic pituitary mass, consistent with pituitary tumor apoplexy. After administration of intravenous glucocorticoids, the patient underwent emergent endoscopic transsphenoidal resection of the pituitary tumor apoplexy. Postoperatively, the patient had neurologic improvement with stable vision. CONCLUSIONS Early and accurate diagnosis is important to allow for timely neurosurgical intervention. Symptoms of fever, hypotension, and tachycardia in a patient with a known sellar mass should raise the suspicion of hypocortisolemia from pituitary tumor apoplexy.

Novel minimally invasive multi-modality monitoring modalities in neurocritical care

Elevated intracranial pressure (ICP) following brain injury contributes to poor outcomes for patients, primarily by reducing the caliber of cerebral vasculature, and thereby reducing cerebral blood flow. Careful monitoring of ICP is critical in these patients in order to determine prognosis, implement treatment when ICP becomes elevated, and to judge responsiveness to treatment. Currently, the gold standard for monitoring is invasive pressure transducers, usually an intraventricular monitor, which presents significant risk of infection and hemorrhage. These risks made discovering non-invasive methods for monitoring ICP and cerebral perfusion a priority for researchers. Herein we sought to review recent publications on novel minimally invasive multi-modality monitoring techniques that provide surrogate data on ICP, cerebral oxygenation, metabolism and blood flow. While limitations in various forms preclude them from supplanting the use of invasive monitors, these modalities represent useful screening tools within our armamentarium that may be invaluable when the risks of invasive monitoring outweigh the associated benefits.

Novel management strategies for medically-refractory vasospasm following aneurysmal subarachnoid hemorrhage

Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) is an important cause of further morbidity and mortality after an already devastating condition. Though traditionally attributed to vasospasm of large capacitance arteries and the resulting down-stream disruption of cerebral blood flow, the pathogenesis of DCI has proven to be more complex with early brain injury, blood-brain barrier disruption, microthrombosis, cortical spreading depolarizations, and the failure of cerebral autoregulation as newly elucidated factors. Vasospasm is a known consequence of SAH. The standard of care includes close monitoring for neurological deterioration, most often with serial clinical examinations, transcranial Doppler ultrasonography, and vascular imaging (crucial for early detection of DCI and allows for prompt intervention). Nimodipine continues to remain an important pharmacological strategy to improve functional outcomes in patients with SAH at risk for developing vasospasm. The paradigm for first line therapy in patients with vasospasm of induced hypertension, hypervolemia, and hemodilution has recently been challenged. Current American Heart Association guidelines recommend targeting euvolemia and judicious use of the pharmacologically induced hypertension component. Symptomatic vasospasm patients who do not improve with this first line therapy require rescue intervention with mechanical or chemical angioplasty and optimization of cardiac output and hemoglobin levels. This can be escalated in a step-wise fashion to include adjunct treatments such as intrathecal administration of vasodilators and sympatholytic or thrombolytic therapies. This review provides a general overview of the treatment modalities for DCI with a focus on novel management strategies that show promising results for treating vasospasm to prevent DCI.

Superior semicircular canal dehiscence: Diagnosis and management

The authors provide an update on the clinical manifestations, diagnosis and various approaches to the treatment of superior semicircular canal dehiscence (SSCD). SSCD is a rare condition where the bone overlying the superior semicircular canal thins or dehisces causing characteristic clinical findings. Since this was first reported in 1998 by Minor and colleagues, there has been much advancement made in terms of diagnosis and treatment. Signs and symptoms include a wide variation of both vestibular and auditory manifestations. Diagnosis made solely on clinical signs is difficult due to how varied the presentations can be and the overlap with other otologic pathologies. High-resolution CT temporal scans have been the standard in confirming superior semicircular canal dehiscence, however, MRI FIESTA scans have recently been used to image SSCD. Additionally, audiometry and vestibular evoked myogenic potential (VEMP) testing are useful screening tools. Currently, the middle fossa approach is the most common and standard surgical approach to repair SSCD. The transmastoid, endoscopic and transcanal or endaural approaches have also been recently utilized. Presently, there is no consensus as to the best approach, material or technique for repair of SSCD. As we learn more, newer and less invasive approaches and techniques are being used to treat SSCD. We present a comprehensive review of SSCD, including clinical symptoms and presentation, histopathology, diagnosis, treatment strategies and outcomes of intervention.

The Role of Fiesta MRI for Assessment of Delayed Enhancement of Fat Graft Packing on Post-operative Imaging after Acoustic Neuroma Surgery

References Conclusion Follow up imaging after acoustic neuroma resection is very important to monitor for tumor recurrence. T1-weighted MRI with gadolinium enhancement is the diagnostic modality of choice for recurrent tumor surveillance. Fat grafts are used after surgical resection of acoustic neuroma to prevent CSF leak, yet several studies have shown that grafts create difficulty in interpreting MR images due to delayed enhancement of graft materials. Due to this enhancement near the IAC, there has been increased use of fat suppression to get a better visualization of the surgical bed. There can also be enhancement of the fat graft in the IAC at 3-6 months after surgery which may indicate tissue reactions to trauma and dural enhancement. These factors create interference in the MR images and create difficulties in identifying potential recurring tumor. FIESTA provides a high resolution image which can be used in conjunction with standard T1 and T2weighted sequences to provide clarity in imaging. This study attempts to show the efficacy of FIESTA imaging in assessing fat grafts in the surgical bed. We hypothesize that the enhancement of the fat graft in T1 with Gadolinium and fat suppression can be resolved when compared with the appearance of the fat graft in FIESTA images.