Multiple Listeria Abscesses in an Immunocompetent Patient.

Listeria monocytogenes is a ubiquitous organism that can potentially cause gastroenteritis and, less commonly, central nervous system infections. Brain abscess is rare and often associated with immunocompromised status. We report a case of multiple abscesses caused by Listeria in a previously immunocompetent elderly patient who developed a headache and left-sided hemiparesis over the course of days. Neuroimaging studies revealed multiple ring-enhancing lesions in the brain and midbrain territories. Blood culture, brain tissue aspirate, and cerebrospinal fluid nucleic acid amplification test were positive for Listeria. Extensive immunologic workup revealed no primary or secondary immunodeficiency disorders. After the initiation of antibiotics, the patient showed gradual clinical improvement and went to a skilled nursing facility after two weeks.

Reversible Cerebral Vasoconstriction Syndrome Due to Midodrine in a Patient with Autonomic Dysreflexia.

Reversible cerebral vasoconstriction syndrome (RCVS) is a rare neurological condition that typically presents with a sudden-onset thunderclap headache associated with or without focal neurological deficits. The diagnosis is established by the presence of reversible segmental or diffuse cerebral vasoconstriction on diagnostic cerebral angiogram. Autonomic dysreflexia is a known complication resulting from spinal cord injury. It manifests as episodes of flushing, headache, and fluctuations in blood pressure. Midodrine is an alpha-1 agonist that causes vasoconstriction and is commonly used in patients with autonomic dysreflexia. Here, we report the case of a young woman with a history of autonomic dysreflexia, who presented with a thunderclap headache and was subsequently diagnosed with reversible cerebral vasoconstriction syndrome.

Propofol and Clevidipine-induced Hypertriglyceridemia.

Hypertriglyceridemia and related pancreatitis due to the use of lipid emulsions such as propofol has been documented, but less is known about the additive adverse effects of propofol and clevidipine lipid emulsions in the literature. We report an unusual case, highlighting the trend of serum triglyceride and pancreatic enzymes (amylase/lipase) with the administration of propofol and clevidipine for a prolonged period in the neurocritical care setting. We present a case of a 27-year-old male who was admitted to the neuroscience intensive care unit (NSICU) for management of severe subarachnoid hemorrhage (SAH) with six-millimeter (mm) midline shift to the left from the rupture of anterior communicating artery aneurysm. The patient was given propofol infusion to maintain sedation and manage intracranial pressures, and clevidipine was chosen over other antihypertensive class for blood pressure management secondary to renal impairment. To focus on the risk of hypertriglyceridemia and associated pancreatitis with the combined use of lipid emulsions we quantified the effect of lipid emulsions on serum triglycerides. We calculated the total calorie and fat content the patient received from the propofol and clevidipine along with the calorie intake from enteral nutrition (Fibersource® tube feed). The patient received a total propofol infusion of 44,391.2 milligrams (mg) over 16 days which accounts for 4,882.99 kilocalories (kcal) and 443.91 grams of fat. He received a total clevidipine infusion of 297 mg over the 48-hour period which contributes 594 kcal and 59.4 grams of fat. The required daily calorie intake through enteral nutrition of Fibresource® was titrated to a goal of 80 mL/hour which provided 2,304 kcal and 76.8 grams of fat each day. We also graphically depicted the rise in the serum triglyceride level after continuous infusion of propofol and clevidipine and subsequent improvement in the amylase and lipase level after the propofol was discontinued. Hence we conclude, careful and periodic monitoring of the serum triglyceride levels and limitation on the total calories from other fat sources such as enteral nutrition can help to mitigate the drug-induced effects.

Cerebral Fat Embolism: Neuroprotective Goals in an Unusual Cause of Altered Mental Status.

Cerebral fat embolism syndrome is a rare, but potentially lethal, complication that may arise from long bone fractures and/or orthopaedic surgery. Neurological symptoms are variable, and clinical diagnosis is difficult. We report the case of a 75-year-old woman who developed cerebral fat embolism four days after a right hip arthroplasty. Maintenance of intracranial pressure monitoring (ICP) within normal limits and cerebral tissue oxygenation monitoring (PbtO2) over 20 mmHg prevented secondary brain injury and resulted in a gradual improvement of the patient's sensorium. This case demonstrates that the use of ICP and PbtO2 monitoring defines optimal neuroprotective goals.

Improvement in Sonographic Vasospasm Following Intravenous Milrinone in a Subarachnoid Hemorrhage Patient with Normal Cardiac Function.

Cerebral vasospasm and delayed cerebral ischemia are well-known complications of an aneurysmal subarachnoid hemorrhage (aSAH), generally occurring days to weeks after hemorrhagic ictus. Management strategies for these complications are controversial and vary in efficacy. There is a growing interest in supporting the use of intravenous (IV) milrinone to manage vasospasm. A 31-year-old male presented to the hospital after being found down outside his home. Computed tomography (CT) of the head and subsequent CT angiogram revealed a Fisher Grade 4 aneurysmal subarachnoid hemorrhage (aSAH). Six hours after admission, he became hypotensive and his neurological examination declined. A repeat CT head showed a new, left frontoparietal intracerebral hemorrhage (ICH) along with increasing SAH. He was stabilized with vasopressors and underwent emergent decompressive hemicraniectomy with subsequent clipping of the aneurysm. Approximately one week later, transcranial Doppler (TCD) showed increasing mean flow velocities in the bilateral anterior and middle cerebral arteries consistent with cerebral vasospasm. He was treated with intravenous milrinone. Repeat TCD 6.5 hours after the initial TCD showed improved mean flow velocities. His cardiac function by echocardiogram assessment was normal. The decrease in TCD velocity following treatment with milrinone indicates an improvement in the cerebral vasospasm regardless of cardiac output in a patient with subarachnoid hemorrhage. This case suggests that augmenting cardiac output may not be the only mechanism for the therapeutic benefit of milrinone.

Somatosensory Evoked Potentials as a Tool to Evaluate Brainstem Herniation in the Neuroscience Intensive Care Unit.

Somatosensory evoked potentials (SSEPs) are a sensitive, minimally invasive technique used to localize dysfunction of myelinated peripheral and central axons in the nervous system. The utility of SSEPs in acutely assessing central nervous system function in brainstem herniation in the neuroscience intensive care unit (NICU) has not been well established. We discuss a case of an 18-year-old, postpartum female who presented with intermittent headache, diplopia, nausea/vomiting and cachexia following delivery two months prior. Shortly after arrival to the emergency department, she developed flaccid quadriparesis and complete ophthalmoplegia. Computed tomography (CT) of the head showed effacement of the basal cisterns along with 2 cm cerebellar tonsillar herniation into the foramen magnum concerning for intracranial hypotension. Raising the head of bed caused hemodynamic instability necessitating prolonged Trendelenburg positioning. The patient was evaluated with serial SSEPs which initially showed a bilateral low amplitude N20 response and normal N13 response. Subsequent SSEP testing showed increased N20 amplitude which correlated with clinical improvement in the patient. SSEP is a minimally invasive and sensitive method used to assess the integrity of the somatosensory nervous system pathway; SSEPs may be a useful monitoring adjunct to assess the evolution of posterior fossa lesions leading to brainstem compression.

Delayed Post-hypoxic Leukoencephalopathy: A Case Series and Review of the Literature.

Delayed post-hypoxic leukoencephalopathy (DPHL) is a unique clinical entity that presents with cognitive impairment days to weeks after an episode of acute hypoxic brain injury. Frequently hypoxia is unrecognized as a mechanism for clinical decline and extensive workup ensues. We present two cases of DPHL highlighting the neuroimaging findings. In both patients, a cerebral hypoxic event was followed by a recovery phase with subsequent delayed clinical decline. Patient 1 suffered hypoxia from drug-induced respiratory depression and lack of post-operative positive airway pressure (PAP) support. Her neurological exam on follow-up revealed progressive cognitive decline. Magnetic resonance imaging (MRI) brain showed bilateral white matter changes involving the centrum semiovale. Patient 2 developed a generalized tonic-clonic seizure during an endobronchial biopsy procedure and was found to have multiple air emboli on computed tomography (CT) head scan. She was initially in a drug-induced coma for her seizures. Electroencephalography (EEG) on day 14 of admission showed changes consistent with diffuse encephalopathy. MRI brain showed bilateral white matter changes particularly at the watershed zones and in the centrum semiovale. DPHL is a rare and under-recognized clinical entity that requires clinical suspicion and detailed evaluation for diagnosis. Neuroimaging studies can provide prognostic information regarding the extent of neurological injury.

Thromboelastography With Platelet Mapping is Not an Effective Measure of Platelet Inhibition in Patients With Spontaneous Intracerebral Hemorrhage on Antiplatelet Therapy.

Thromboelastography with platelet mapping (TEG-PM) is a modality to measure platelet function, especially in patients taking antiplatelet medications. It consists of two components: arachidonic acid (AA), which is sensitive to aspirin, and adenosine diphosphate (ADP), which is sensitive to clopidogrel. In patients with spontaneous intracerebral hemorrhages (sICH), the clinical interpretation of platelet mapping is unclear. The objective of this study was to evaluate TEG-PM in patients with sICH on aspirin and/or clopidogrel who receive platelet transfusions. This study was an IRB-approved, retrospective case-control study over three years at an academic medical center. Adult patients with sICH were included if they had an admission computed tomography head (CTH) and platelet mapping followed by a repeat platelet mapping and CTH post platelet transfusion. A threshold of 50% inhibition was used as the benchmark for both ADP and AA inhibition. Around 248 subjects with sICH were identified, and 107 were excluded for incomplete documentation, leaving 141 for analysis. Of these, nine met our inclusion criteria. No statistical significance was found on the antithrombotic effects of aspirin or clopidogrel on TEG-PM (p=1.00 for both). Sensitivity and specificity of TEG-PM for clopidogrel was 100% and 42.9%, respectively, and 80% and 0%, respectively, for aspirin. Platelet transfusion did not significantly change AA or ADP inhibition (p=1.00). Hemorrhagic expansion on CTH was not associated with a decrease AA or ADP inhibition (p=1.00). TEG-PM is not an effective measure of platelet inhibition in sICH patients who were on antiplatelet medications and is not a reliable measurement following platelet transfusion.

An Evaluation of Complications in Femoral Arterial Sheaths Maintained Post-Neuroangiographic Procedures.

BACKGROUND: Digital subtraction angiography (DSA) is a frequently used technique in the neuro-diagnosis and treatment of cerebrovascular diseases. The routine use of femoral arterial sheaths (FAS) peri-procedurally has become standard. The maintenance of a FAS post-procedure may be warranted while awaiting the normalization of coagulopathy or to reaccess emergently. We retrospectively reviewed our stroke dataset to evaluate for complications associated with the prolonged use of FAS post-procedure. METHODS: A retrospective chart review was performed over a five-month period, including adult patients admitted to the neuroscience intensive care unit (NSICU) following a neuro-endovascular procedure at a tertiary healthcare facility. The patients' age and sex along with catheter size, duration of sheath placement, coagulation status, usage of heparinized-saline, reuse of FAS for angiographic interventions, and closure technique employed when sheath was removed were recorded. FAS were maintained and evaluated by the neurocritical care team for vascular complications according to protocols. Furthermore, patients were categorized as delayed extubation when they remained intubated post-procedure. A spontaneous breathing trial was performed once FAS could be removed following evaluation. Data were expressed with descriptive statistics. RESULTS: One hundred and seventy-eight neuro-endovascular procedures were reviewed. Fourteen patients in which the sheaths were left in place for a prolonged period of time after the procedure were identified with seven (50%) having complications. The most common complication was delayed extubation, which was noted in all seven of the patients with complications. Bleeding complications were noted in four (28.6%). None had thromboembolic complications. Only one FAS was reaccessed for the evaluation of vasospasm and the introduction of intra-arterial verapamil. There was a linear increase in complications with the duration the catheter remained in place after the procedure. CONCLUSION: The practice of keeping FAS in for a prolonged period of time following procedures should be evaluated given the association with direct and indirect complications and minimal need to reaccess the catheter after the procedure.

Trans-cranial Doppler as an Ancillary Study Supporting Irreversible Brain Injury in a Post Cardiac Arrest Patient on Extracorporeal Membrane Oxygenation.

Obtaining neuroimaging in patients on cardiopulmonary support devices such as extracorporeal membrane oxygenation (ECMO) can be challenging, given the complexities in monitoring, instrumentation, and associated hemodynamic lability. Transcranial Doppler (TCD) is used as an ancillary test for the assessment of cerebral circulatory arrest, but its use in non-pulsatile blood flow in venoarterial (VA) ECMO is not well described. We report the use of TCD in a patient on VA ECMO post-cardiac arrest for evaluation of death by neurological criteria. A 72-year-old female was admitted for elective trans-catheter aortic valve replacement. Her postoperative course was complicated by hemo-pericardium evolving into pulseless electrical activity causing cardiac arrest. She was resuscitated with return of spontaneous circulation and initiated on VA ECMO and intra-aortic balloon pump for cardiogenic shock. Over the next few days, serial evaluations persistently showed a poor neurological examination. She was too unstable to transport for neuroimaging. Evaluation for death by neurological criteria was performed with a clinical examination, apnea testing, and TCD as an ancillary study. TCD showed systolic spikes supporting an impression of cerebral circulatory arrest consistent with an irreversible brain injury.

Pitfall in Pupillometry: Exaggerated Ciliospinal Reflex in a Patient in Barbiturate Coma Mimicking a Nonreactive Pupil.

Although a neurological examination is fundamental to the evaluation of comatose patients, it is less reliable in a medically induced coma. A commonly misinterpreted finding in patients in a pentobarbital coma is altered pupillary reactivity secondary to an exaggerated ciliospinal reflex. Recognizing an exaggerated ciliospinal reflex in patients in a pentobarbital coma is important and may prevent unnecessary intervention. We present a patient induced in a pentobarbital coma for the treatment of status epilepticus who exhibited a nonreactive pupil secondary to an exaggerated ciliospinal reflex confirmed by pupillometry. We also discuss the anatomy of the ciliospinal reflex and literature regarding its clinical relevance.