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Neurological Disease
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
In this rare condition, a central fluid-filled cavity develops in the spinal cord (syringomyelia) or brainstem (syringobulbia). It may be associated with congenital abnormalities at the foramen magnum or occur secondary to a tumour of the cord or to trauma. The expanding cavity compresses sensory fibres crossing the midline on their way to join the lateral spinothalamic tract; later, it may also compress the corticospinal tracts. There is loss of pain and temperature (but not light touch, proprioception or vibration) sensation at the segmental levels of the syrinx along with reflex loss at that level. As symptoms progress UMN signs may develop in the legs.
Specialized Circulations in Susceptible Tissues
Published in Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos, McDonald's Blood Flow in Arteries, 2022
The carotid arteries transmit some 75 percent of blood needed by the brain into the cranium. Most of the rest comes from the vertebral arteries on each side, which ascend through the transverse processes of cervical vertebrae, then enter the dural sac, pass through the foramen magnum into the cranium where they join to form the basilar artery, which links with branches of the carotid artery to form the Circle of Willis and connects all arteries that enter the skull to supply the brain, brainstem and upper part of the spinal cord. Venous blood collects in the venous sinuses before exiting the cranium through the right and left jugular veins into the neck. Approximately one liter of blood runs through this path every minute. Other spinal arteries enter the spinal canal with the nerves that join the rest of the spinal cord in the canal; the spinal canal ends at the level of the lowest lumbar vertebra. The spinal cord connects with the brain at the foramen magnum. Cerebrospinal fluid bathes the brain and spinal cord in the subarachnoid space of the cranium and spinal cord. The cerebral arteries and veins in the cranium run in the subarachnoid space. The veins have no valves. Valves are not needed for blood to leave the normal skull.
Cranial Neuropathies I, V, and VII–XII
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Skull and foramen magnum lesions: these lesions usually also involve contiguous cranial nerves (IX, X, XI, and XII) and may also affect the medulla or upper cervical cord. Possible etiologies include neoplasms (meningiomas, dermoids), meningeal processes, and traumatic injuries.
What is the best treatment option for cervical spinal cord injury by os odontoideum in a patient with athetoid dystonic cerebral palsy?
Published in The Journal of Spinal Cord Medicine, 2021
Sungche Lee, Dong Hyun Kim, Yoon-Hee Choi
There are two main approaches for patients with OO, non-surgical and surgical approaches. When the risks of neurologic deterioration during and following surgical procedures outweigh benefits of fixation or patient maintains a stable OO condition, a non-surgical approach is also preferred.3,5,14 However, a surgical approach can be chosen when there are conditions affecting the foramen magnum and craniocervical junction and/or to stabilize the cervical spine. The surgical approach is usually selected among occipitocervical fusion and C1–C2 screw fixation with or without anterior/posterior decompression via an anterior or posterior approach. Different patient prognoses have been reported for the non-surgical and surgical approaches. And, currently, there are no evidence-based standard guidelines for OO treatment.8,12,13,15–18
Change in gene expression levels of GABA, glutamate and neurosteroid pathways due to acoustic trauma in the cochlea
Published in Journal of Neurogenetics, 2021
Meltem Cerrah Gunes, Murat Salih Gunes, Alperen Vural, Fatma Aybuga, Arslan Bayram, Keziban Korkmaz Bayram, Mehmet Ilhan Sahin, Muhammet Ensar Dogan, Sevda Yesim Ozdemir, Yusuf Ozkul
Control mice were sacrificed after the initial DPOAE measurements without being exposed to noise. Post-AT(1) mice and Post-AT(15) mice were sacrificed on day 1 and day 15 after the noise exposure, respectively. Under identical deep general anaesthesia, the mouse was decapitated with scissors. The skin of the head was dissected from posterior to anterior as far as the orbits. The dorsal skull was split from the foramen magnum to the orbits and cut laterally, posterior to the orbits, on both sides. The bony flaps were bent outward and the brain was removed afterwards. The bony labyrinths were recognized anterior to the foramen magnum in the base of the skull. The fibrous connections between the temporal bones and the rest of the skull were dissected and the temporal bones were separated from the skull on both sides. Next, the bulla was opened, and the cochlea was located under the microscope. Then, the malleus, incus and stapes were removed. While fixing the temporal bone with forceps, the bony wall of the cochlea was cracked with other forceps by holding between the oval and round windows and taken off piece by piece carefully. After peeling the bone all around the cochlea, membranous structures were removed completely and put in the Eppendorf Tube with 1 ml Trizol solution and mixed at room temperature until dissolving the content. Then they stored at −80 °C.
Mechanistic reasoning in neursourgery
Published in British Journal of Neurosurgery, 2019
Decision making in neurosurgery is dominated both by working out what operations to recommend to which patients. Sometimes we are fortunate enough to have high class observation of data on which to base these recommendations such as who should be offered surgery for brain haemorrhage removal or who should be offered decompressive craniectomy. More commonly decisions are informed by simple widely held mechanistic models of disease pathophysiology and treatment in disc surgery or shuntology. Then there are the areas that really vex us. Those where we do not have good observational data and simple mechanistic models are either contradictory or unhelpful. We all have areas of practice beset with these difficulties. Treatment of symptomatic foramen magnum obstruction from Chiari malformations and symptomatic benign intracranial hypertension particularly spring to mind.