0000000000745880
AUTHOR
Cole A. Giller
A Strange Case of Downward Displacement of a Deep Brain Stimulation Electrode 10 Years Following Implantation: The Gliding Movement of Snakes Theory.
Background Despite the best efforts to ensure stereotactic precision, deep brain stimulation (DBS) electrodes can wander from their intended position after implantation. We report a case of downward electrode migration 10 years following successful implantation in a patient with Parkinson disease. Methods A 53-year-old man with Parkinson disease underwent bilateral implantation of DBS electrodes connected to a subclavicular 2-channel pulse generator. The generator was replaced 7 years later, and a computed tomography (CT) scan confirmed the correct position of both leads. The patient developed a gradual worsening affecting his right side 3 years later, 10 years after the original implantati…
Delayed chronic intracranial subdural hematoma complicating resection of a tanycytic thoracic ependymoma
Background To demonstrate that the diagnosis of an intracranial subdural hematoma should be considered for patients presenting with acute or delayed symptoms of intracranial pathology following resection of a spinal tumor. Case description We present a case of a 57-year-old woman found to have a chronic subdural hematoma 1 month following resection of a thoracic extramedullary ependymoma. Evacuation of the hematoma through a burr hole relieved the presenting symptoms and signs. Resolution of the hematoma was confirmed with a computed tomography (CT) scan. Conclusion Headache and other symptoms not referable to spinal pathology should be regarded as a warning sign of an intracranial subdural…
Use of middle cerebral velocity and blood pressure for the analysis of cerebral autoregulation at various frequencies: The coherence index
A common component in many protocols for the evaluation of cerebral autoregulation is the comparison of transcranial Doppler ultrasound (TCD) velocities with blood pressure recordings, in which correlations between these two signals correspond to impaired autoregulation. With long data sets and complicated paradigms, however, visual inspection alone cannot adequately distinguish random coincidence from consistent correlation in a statistically valid fashion. We suggest and illustrate the use of the coherence index for this purpose. To illustrate this technique, long-term recordings of TCD velocity and blood pressure were obtained from 6 normal subjects and using 23 data segments from 8 pati…