Neurodiagnostics, Pharmacology, and Patient Safety
Neurodiagnostics: Testing, Preparation, and Interpretation
Structural imaging
Noncontrast head CT is first line for acute hemorrhage, mass effect, and hydrocephalus; it is fast and generally safe with implanted devices. MRI gives superior soft-tissue detail for infarct, tumor, demyelination, and infection but requires metal and device screening and longer immobility. CTA and MRA show vessels; conventional angiography (DSA) is the reference standard but is invasive, with stroke, dissection, and contrast/renal risk. Contrast studies require creatinine/eGFR review and allergy premedication per protocol.
CSF and EEG
Lumbar puncture: lateral decubitus with knees to chest; adult opening pressure is roughly 10–20 cm H2O. Contraindications include signs of raised ICP or herniation, coagulopathy, and infection at the site; image first when focal findings or papilledema are present. Post-LP headache is postural - flat rest and hydration help. EEG evaluates seizure activity and encephalopathy; preparation includes hair washing, no caffeine, and following orders about sleep deprivation and whether to hold antiseizure medication.
Physiologic testing
EMG and nerve conduction studies separate myopathy from neuropathy. Evoked potentials assess specific pathways. Transcranial Doppler detects vasospasm after SAH through elevated MCA mean flow velocities and screens for sickle cell vasculopathy. Neuropsychological testing characterizes cognition and mood.
Traps
Sending a patient to MRI without device screening; ordering LP before imaging in a patient with papilledema or a new focal deficit; assuming a normal CT excludes ischemic stroke, since early infarcts are often invisible.
Rule of thumb: imaging answers where and what; EEG answers whether it is electrical; LP answers whether it is infectious or inflammatory. Document baseline neuro status and allergies before any study.
Neuropharmacology and Medication Safety
Antiseizure medications
Levetiracetam is widely used for prophylaxis and status epilepticus; watch for behavioral change. Phenytoin and fosphenytoin must be diluted in normal saline only, given through a filter, and infused no faster than 50 mg/min (slower in older adults) with cardiac monitoring because of hypotension and arrhythmia; extravasation causes purple glove syndrome. Track levels and albumin.
Osmotic and steroid therapy
Mannitol requires an in-line filter; monitor osmolality, renal function, and volume status, because it transiently expands plasma volume before diuresis. Hypertonic saline at higher concentrations needs central access and frequent sodium checks. Dexamethasone reduces tumor-associated edema but is contraindicated in traumatic brain injury.
Antithrombotics and reversal
Alteplase for acute stroke is weight-based; contraindication screening and BP control matter more than the pump. Know reversal: protamine for heparin, vitamin K or PCC for warfarin, idarucizumab for dabigatran, and factor Xa reversal agents where available. Hold anticoagulants before LP and surgery per protocol.
Neuro-specific agents
Nimodipine after SAH commonly lowers blood pressure - notify the provider rather than simply skipping doses. Carbidopa/levodopa timing is part of the prescription. Intrathecal baclofen withdrawal after pump failure is a medical emergency. Pyridostigmine treats myasthenia gravis. Analgesia and sedation in the neuro ICU can mask the examination, so use short-acting agents and document a baseline before sedating.
Traps
Mixing phenytoin in dextrose, infusing it without a filter, giving steroids to a TBI patient, and accepting a sedated exam as the true neurologic baseline.
Rule of thumb: for any high-alert neuro drug know four things - diluent and route, maximum rate, monitoring parameter, and antidote or reversal agent.
Patient Safety and Risk Reduction in Neuroscience Care
Dominant harms
Falls, aspiration, pressure injury, VTE, delirium, and device complications drive most neuroscience harm. Screen swallow before oral intake in stroke, TBI, Parkinson disease, and ALS; keep the patient NPO until screening is complete. Seizure precautions include a low bed, padded rails, suction, and oxygen at the bedside, with no restriction beyond policy. Reposition every two hours, but individualize for ICP elevation and spinal instability.
Device safety
External ventricular drains must be leveled to the prescribed landmark (commonly the tragus or foramen of Monro), never flushed, and clamped per policy before repositioning or transport. Track CSF volume, color, and culture results. Shunt malfunction presents as headache, vomiting, and lethargy - escalate promptly. Never stop an intrathecal baclofen pump abruptly.
Medications and handoff
Alteplase, heparin, insulin, and opioids are high-alert drugs. Use two identifiers, weight-based double checks, and independent verification of continuous infusions. Handoff should state out loud the baseline neuro exam, last known well, ICP/CPP targets, drain settings, and any time-critical treatment window.
Dysreflexia and restraints
For spinal cord injury at T6 or above, acute hypertension with headache is an emergency: sit the patient up, remove constriction, and check bladder and bowel. Restraints require an order, time-limited monitoring, and reassessment - never as a substitute for adequate staffing or supervision.
Traps
Flushing an EVD 'to check patency,' leaving a drain unleveled after raising the bed, completing a fall-risk score without acting on it, and accepting a 'stable' report that omits the neurologic baseline.
Rule of thumb: if a patient has a drain, an unprotected airway, or pressure injury risk and the plan cannot state the parameter and the escalation threshold, the plan is incomplete.