2.3 Physical and Neurological Assessment in Psychiatry

2.3 Physical and Neurological Assessment in Psychiatry

Core Concept: Psychiatric illnesses do not exist in a vacuum; the brain is intricately connected to the body. A PMHNP must be proficient in targeted physical and neurological examinations to distinguish primary psychiatric disorders from medical mimics and to monitor for the somatic side effects of psychotropic medications.

While a full physical exam may not be conducted at every psychiatric visit, targeted assessments are mandatory based on the patient's presentation and medication regimen.

The Physical Examination in Psychiatry

Certain physical findings provide critical clues to underlying psychiatric or substance use disorders:

• Vital Signs: Essential for detecting medication side effects (e.g., hypertension from SNRIs or stimulants, tachycardia from clozapine) or medical emergencies (e.g., fever and autonomic instability in Neuroleptic Malignant Syndrome [NMS] or Serotonin Syndrome).
• Skin/Integumentary: Look for track marks (IV drug use), excoriations (methamphetamine use, 'meth mites'), self-harm scars (borderline personality disorder), or lanugo (fine body hair seen in severe anorexia nervosa).
• HEENT (Head, Eyes, Ears, Nose, Throat):
  • Pupils: Pinpoint (opioid intoxication), dilated (stimulant intoxication or opioid withdrawal).
  • Nasal Septum: Perforation (chronic cocaine snorting).
  • Dentition: Severe decay ('meth mouth', bulimia nervosa).
• Thyroid: Palpation for goiter. Hyperthyroidism can mimic anxiety/mania; hypothyroidism can mimic depression.

Vital Sign Patterns in Psychiatric Emergencies

The Neurological Examination

A thorough neurological exam is particularly important for patients presenting with first-episode psychosis, new-onset cognitive decline, or atypical symptoms.

1. Cranial Nerves (CN II-XII)

Deficits in cranial nerves strongly suggest an organic, structural brain lesion (e.g., tumor, stroke) rather than a primary psychiatric illness. For example, a patient presenting with new-onset paranoia who also exhibits a visual field cut (CN II) or facial droop (CN VII) requires immediate neuroimaging.

Specific psychiatric correlations include:

• CN I (Olfactory): Anosmia is a prodromal sign of Parkinson's disease and Alzheimer's; olfactory hallucinations suggest temporal lobe epilepsy.
• CN III, IV, VI: Nystagmus occurs with lithium toxicity, PCP/ketamine intoxication, and Wernicke's encephalopathy.
• CN VII: Masked facies occurs in antipsychotic-induced parkinsonism and Parkinson's disease.
• CN XII: Darting or choreoathetoid tongue movements are classic for tardive dyskinesia; fasciculations suggest ALS.

2. Motor System and Movement Disorders

Assessing motor function is critical, primarily to monitor the adverse effects of dopamine receptor antagonists (antipsychotics).

Extrapyramidal Symptoms (EPS): These result from dopamine blockade in the nigrostriatal pathway.

• Acute Dystonia: Sustained, painful muscle contractions (e.g., torticollis, oculogyric crisis). Usually occurs within hours to days of starting a medication. Treated with anticholinergics (benztropine, diphenhydramine).
• Akathisia: Subjective feeling of inner restlessness and the objective urge to move constantly (pacing, rocking). Often misdiagnosed as worsening anxiety. Treated with beta-blockers (propranolol) or dose reduction.
• Parkinsonism: Characterized by the classic triad of:
  1. Resting Tremor: "Pill-rolling" tremor.
  2. Rigidity: Cogwheel rigidity (ratchet-like resistance during passive movement of a joint).
  3. Bradykinesia: Slowed movements, masked facies, shuffling gait.

Tardive Dyskinesia (TD): A delayed-onset, potentially irreversible movement disorder characterized by choreoathetoid (writhing, jerky) movements, most commonly affecting the orofacial region (lip-smacking, tongue protrusion). It results from chronic dopamine blockade leading to receptor supersensitivity.

The Abnormal Involuntary Movement Scale (AIMS)

The AIMS is the gold-standard assessment tool for TD. It is a structured, 12-item observational exam.

• Requirement: Must be performed at baseline before starting an antipsychotic, and every 3-6 months thereafter (more frequently for first-generation antipsychotics or high-risk patients).
• Assessment Areas: Facial/oral movements, extremity movements, and trunk movements.
• Administration Technique: Observe the patient seated with hands dangling between knees, then standing; observe gait. Ask the patient to open mouth, protrude tongue, and tap thumb with each finger. Document frequency, amplitude, and location of movements.

Differentiating Akathisia from Agitation: A Common Exam Trap

Akathisia is frequently misdiagnosed as worsening psychosis or anxiety. The PMHNP must distinguish: Akathisia presents as an intolerable internal restlessness that improves with movement and emerges within days-to-weeks of an antipsychotic dose increase. Agitation/psychosis is driven by disorganized thought content and does not reliably remit with pacing. Misdiagnosing akathisia as agitation and increasing the antipsychotic dose creates a dangerous spiral of worsening restlessness and impulsivity, including elevated suicide risk.

3. Neurological Soft Signs (NSS)

Unlike 'hard' signs (like a cranial nerve palsy) that localize a lesion to a specific brain area, 'soft' signs indicate subtle, generalized, non-localizing cortical dysfunction or neurodevelopmental abnormalities. They are highly prevalent (50-75%) in patients with schizophrenia.

Common NSS to assess:

• Dysdiadochokinesia: Inability to perform rapid alternating movements (e.g., quickly flipping hands back and forth on the thighs).
• Astereognosis: Inability to identify an object by touch alone with eyes closed.
• Agraphesthesia: Inability to identify numbers or letters traced on the palm of the hand.
• Gait Abnormalities: Tandem walking difficulties.

4. Frontal Release Signs (Primitive Reflexes)

The re-emergence of primitive reflexes suggests frontal lobe pathology (e.g., severe dementia, advanced schizophrenia).

• Snout Reflex: Pouting of the lips when the upper lip is tapped.
• Grasp Reflex: Involuntary grasping of an object placed in the palm.
• Palmomental Reflex: Twitching of the chin muscle when the palm is stroked.

Deep Tendon Reflexes and Their Psychiatric Significance

• Hyperreflexia with clonus: Pathognomonic for Serotonin Syndrome (differentiates from NMS, which presents with hyporeflexia).
• Hyporeflexia/Areflexia: Severe lithium toxicity, hypothyroidism, lower motor neuron lesions.

Integrating the physical and neurological exam into psychiatric practice ensures comprehensive care, preventing the misattribution of medical/neurological pathology to primary psychiatric disorders.