What is the appropriate workup for a 64-year-old male with no recent medication changes, who experienced sleep walking and falls 4 nights ago, resulting in a fracture to the occipital and parietal bone, and was reported to be catatonic in bed at one point, with no recall of the events?

Differential Diagnosis and Workup for Nocturnal Falls with Skull Fracture and Catatonic Episode

Primary Differential Diagnosis

This presentation most likely represents REM Sleep Behavior Disorder (RBD) given the violent nocturnal motor activity, amnesia for events, and resultant serious injury (skull fracture), though nocturnal seizures and acute confusional states must be excluded. 1

The key differentiating features are:

REM Sleep Behavior Disorder

• Multiple violent falls in one night with complete amnesia strongly suggests RBD, where patients act out dreams during REM sleep with loss of normal muscle atonia 1
• The "catatonic" episode described by the wife may represent the post-episode confusion or the actual REM sleep state with abnormal muscle tone 2
• RBD carries 30-81% risk of sleep-related injury in diagnosed patients, with fractures and subdural hematomas well-documented 1
• Age 64 fits the typical demographic for RBD 2, 3

Nocturnal Frontal Lobe Epilepsy

• Would typically show stereotypic, repetitive attacks recurring multiple times per night and across different nights 2
• Less likely given the single-night occurrence and lack of recurrence over 4 nights 2

Catatonia (Secondary to Medical Cause)

• The witnessed "catatonic" state requires investigation for metabolic, neurologic, or toxic causes 4, 5, 6
• Hyponatremia, cerebral venous sinus thrombosis, and other medical conditions can induce catatonia 4
• However, catatonia alone does not explain the violent nocturnal motor activity and falls 4, 6

Syncope/Orthostatic Hypotension

• Less likely given multiple falls in rapid succession and the violent nature of activity 1
• Would not explain the catatonic episode 1

Essential Immediate Workup

Neuroimaging (Already Completed)

• CT head has documented occipital and parietal fractures - monitor for delayed complications including subdural hematoma 1
• MRI brain with and without contrast is indicated to evaluate for:
  • Structural lesions causing seizures 2
  • Cerebrovascular disease 1, 4
  • Neurodegenerative changes (RBD is associated with synucleinopathies) 1

Polysomnography (PSG)

• Video polysomnography is the diagnostic gold standard for RBD and nocturnal seizures 1, 2
• Must assess for REM sleep without atonia (RSWA) - sustained tonic or excessive phasic muscle activity during REM sleep 1
• Captures nocturnal seizure activity if present 2
• Home audio-video recordings of episodes should be obtained if available to supplement PSG 2

Electroencephalography (EEG)

• Extended EEG monitoring (ideally 24-hour ambulatory EEG) to evaluate for nocturnal seizures, particularly frontal lobe epilepsy 2
• Standard EEG may miss nocturnal frontal lobe epilepsy 2

Laboratory Evaluation

• Comprehensive metabolic panel including sodium, glucose, calcium, magnesium - hyponatremia and other metabolic derangements can cause catatonia 4
• Complete blood count 7
• Thyroid function tests 4
• Vitamin B12 and folate 4
• Creatine kinase if catatonia suspected (elevated in neuroleptic malignant syndrome) 4, 5
• Toxicology screen 4
• Anti-NMDA receptor antibodies if autoimmune encephalitis suspected 4

Cardiovascular Assessment

• ECG to evaluate for arrhythmias 7
• Orthostatic vital signs (supine, sitting, standing at 1 and 3 minutes) - orthostatic hypotension can contribute to falls in elderly 1, 7
• Carotid sinus massage (supine and upright) given age >40 years - carotid sinus syndrome causes up to 20% of syncope/falls in this age group 1

Cognitive and Psychiatric Assessment

• Mini-Mental State Examination or Mini-Cog - cognitive impairment affects recall accuracy and is present in 5% of 65-year-olds 1, 8
• Depression screening with PHQ-2 8
• Formal psychiatric evaluation if catatonia confirmed 4, 5, 6

Medication Review

• Comprehensive review of all medications including over-the-counter and supplements, focusing on:
  • Psychotropic medications (antipsychotics, antidepressants, benzodiazepines) 1
  • Recent discontinuation of benzodiazepines or clozapine (can precipitate catatonia) 4
  • Sedative-hypnotics 7, 8
  • Vasodilators and diuretics 7, 8

Additional Assessments

Physical Examination Priorities

• Detailed neurological examination including gait, balance (eyes open and closed), proximal muscle strength, and assessment for neuropathies 1, 7
• Timed Up and Go test - >12 seconds indicates high fall risk 8
• Visual acuity testing 8
• Signs of catatonia: immobility, mutism, staring, rigidity, waxy flexibility 4, 5, 6

Witness Account

• Detailed interview with wife is critical - up to 40-60% of elderly fall patients lack witness accounts 1
• Specific questions about:
  • Exact sequence of events and timing 1
  • Nature of movements (violent, purposeful, stereotyped) 2
  • Duration of "catatonic" state 4, 5
  • Any vocalizations or dream enactment behavior 1
  • Previous similar episodes 1

Immediate Safety Interventions

Regardless of final diagnosis, immediate environmental modifications are mandatory given the serious injury sustained:

• Place mattress on floor 1
• Remove all potentially dangerous objects from bedroom including sharp objects and weapons 1
• Pad corners of furniture and consider window protection 1
• Wife should sleep in separate room until diagnosis established and treatment initiated 1
• Consider padded bed rails (though avoid active restraints which can cause injury with sudden movements) 1

Treatment Considerations Pending Workup

If RBD Confirmed

• Clonazepam 0.25-2.0 mg at bedtime is first-line pharmacologic therapy (reduces sleep-related injury rate from 80.8% to 5.6%) 1
• Use with extreme caution or avoid if gait disorder, dementia, or sleep apnea present 1
• Melatonin is increasingly used as first-line, especially with cognitive impairment or sleep apnea 1

If Catatonia Confirmed

• Lorazepam challenge test (1-2 mg IV/IM) - dramatic rapid response confirms diagnosis 4, 5, 6
• Benzodiazepines are first-line treatment 4, 5, 6
• Electroconvulsive therapy if benzodiazepines fail 4, 5, 6

If Seizures Confirmed

• Antiepileptic therapy per neurology consultation 2
• Carbamazepine has some evidence for nocturnal seizures 1

Critical Pitfalls to Avoid

• Do not dismiss this as simple "sleepwalking" - the violence, injury severity, and catatonic episode demand comprehensive workup 1, 2, 3
• Do not prescribe benzodiazepines empirically before PSG if RBD suspected - may suppress diagnostic findings and worsen sleep apnea if present 1
• Do not overlook neurodegenerative disease screening - RBD has high association with future development of Parkinson's disease and dementia with Lewy bodies 1
• Do not attribute falls solely to age - this patient requires multifactorial fall risk assessment given high-risk features 1, 7, 8
• Do not restart patient on any recently discontinued psychiatric medications without full evaluation - withdrawal can precipitate catatonia 4

Follow-up Plan

• Neurology consultation for PSG interpretation and management 1
• Physical therapy referral for gait and balance training (3+ days/week balance training, twice weekly strength training) 7, 8
• Occupational therapy home safety evaluation with direct intervention 1, 7, 8
• Bone health evaluation with DEXA scan given skull fracture and fall risk 7, 8
• Vitamin D supplementation 800 IU daily 7, 8
• Close monitoring for recurrence - patient is at extremely high risk for repeat injury 1, 7