TEN Neurologia common mistakes
TEN Neurologia · Understand the traps and how to avoid them.
Jumping to a single lesion localization from the first symptom reported (e.g., calling a facial droop a peripheral facial palsy) without testing the rest of the cranial nerves and long tracts to confirm or refute the localization.
Candidates anchor on the most visually striking finding and stop the exam early; the source specifies no sub-topics, so they rely on pattern recognition instead of a systematic neuro exam.
What to do instead
Before committing to a localization, explicitly run through a fixed checklist (12 cranial nerves, motor, sensory, reflexes, coordination, gait) and state which findings are present, absent, and incompatible with the proposed lesion. Write the localization and the supporting/refuting findings in one line.
Confusing upper and lower motor neuron signs when describing weakness (e.g., labeling spasticity with hyperreflexia as a lower motor neuron lesion, or fasciculations with atrophy as upper motor neuron).
The UMN/LMN distinction is taught early and then assumed; under time pressure candidates recall 'weakness' generically and misassign tone, reflexes, and atrophy.
What to do instead
Memorize the five-column contrast (tone, reflexes, Babinski, atrophy, fasciculations) and force yourself to assign each column for every weakness case before answering. Practice by writing the table from memory and applying it to three vignettes.
Misinterpreting cerebrospinal fluid profiles, calling a lymphocytic pleocytosis with normal glucose 'bacterial' or a neutrophilic profile with low glucose 'viral', without integrating opening pressure and clinical tempo.
CSF patterns are memorized as single numbers rather than as a profile; candidates fixate on cell count and ignore glucose ratio, protein, and pressure.
What to do instead
Build a four-row CSF grid (opening pressure, cells and differential, glucose ratio to serum, protein) for bacterial, viral, TB/fungal, and autoimmune/neoplastic patterns, and rehearse it until you can fill it in under a minute. Always state the glucose as a ratio, not an absolute value.
Failing to distinguish peripheral from central vertigo before selecting a diagnosis, answering 'vestibular neuritis' for a patient with direction-changing nystagmus or a positive HINTS central pattern.
Dizziness is the highest-volume presenting complaint in neurology and candidates use symptom severity as a proxy for central versus peripheral, which is unreliable.
What to do instead
Apply HINTS (head impulse, nystagmus type, test of skew) and the presence of truncal ataxia as a routine; if any central feature is present, the answer is a central cause regardless of how 'benign' the history sounds. Practice HINTS interpretation on paper vignettes.
Under-recognizing stroke mimics and over-recognizing stroke, e.g., giving thrombolysis in a seizure with Todd paresis or withholding it in a posterior circulation syndrome because the NIHSS is low.
Time pressure and the 'act fast' framing push candidates toward the thrombolysis answer whenever stroke is mentioned, while posterior circulation deficits score deceptively low on the NIHSS.
What to do instead
Before any reperfusion answer, check four boxes: symptom onset time, glucose, contraindications, and whether the deficit is explained by a non-vascular cause. Separately memorize that low NIHSS with disabling posterior circulation deficit still qualifies, and state the reasoning explicitly.
Mismanaging status epilepticus and seizure classification, e.g., choosing a second-line agent before a benzodiazepine, or mislabeling a focal impaired awareness seizure as absence because the patient 'stared'.
Seizure semiology is described in prose that candidates skim, and the treatment ladder is recalled as a list without the timing thresholds that make each step correct.
What to do instead
Memorize the time-anchored ladder (first-line benzodiazepine at 5 minutes, second-line at 20 minutes, refractory at 40 minutes) and the semiology discriminators (duration, postictal confusion, automatisms, EEG pattern). For each vignette, write the seizure type and the next drug with its timing before reading the options.
Applying adult headache red-flag logic inconsistently, missing secondary headache in a patient with a new headache and a normal exam, or over-investigating a stable primary headache.
Headache questions reward pattern matching to migraine or tension-type, and candidates skip the red-flag screen once the pattern feels familiar.
What to do instead
Run the SNOOP4 screen (systemic symptoms, neurologic signs, onset sudden, older age, pattern change, positional, papilledema, pregnancy, painkiller overuse) on every headache vignette and document which flags are present. Only then choose between primary and secondary.
Misreading the temporal profile of neuromuscular disease, e.g., diagnosing Guillain-Barré syndrome in a patient with subacute ascending numbness and hyperreflexia, or missing myasthenia in a patient with fatigable ptosis and normal reflexes.
Neuromuscular disorders share overlapping weakness descriptions, and candidates match on 'ascending weakness' without checking reflexes, sensory level, and fatigability.
What to do instead
Use a three-question discriminator for every weakness case: are reflexes increased, normal, or absent; is there sensory involvement; and is weakness fatigable. Map the answers to the UMN, peripheral nerve, neuromuscular junction, and muscle categories before naming a disease.
Ignoring the medication and toxic-metabolic history when interpreting encephalopathy, attributing confusion to a primary dementia or psychiatric cause without checking drugs, sodium, ammonia, or glucose.
Encephalopathy vignettes are written to look like dementia, and candidates commit to a neurodegenerative answer before screening reversible causes.
What to do instead
For any confusion or altered mental status, first list the reversible causes by system (drugs, electrolytes, glucose, infection, hypoxia, hepatic/renal, thyroid, thiamine) and eliminate them explicitly. Treat 'delirium' as a syndrome requiring a cause, not a diagnosis.
Answering imaging and diagnostic-test questions by test prestige rather than test properties, e.g., choosing MRI for an acute hemorrhage or skipping a non-contrast CT in acute stroke, and not justifying the choice with sensitivity, timing, or contraindication.
Candidates associate MRI with 'better' and forget that availability, speed, and the clinical question determine the correct first test in acute neurology.
What to do instead
For each diagnostic question, state the clinical question, the time window, and the test's constraint (speed, radiation, contrast, availability) in one sentence before choosing. Memorize the acute-stroke rule that non-contrast CT excludes hemorrhage first and that MRI is the test for posterior fossa and demyelination.