Huntington's Disease (Acute Presentation)MANAGEMENT

SYSTEMIC AND MISCELLANEOUS PRESENTATIONS · 12 SECTIONS

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690 items

☷ Legend

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Cardiovascular Presentations71▾

Respiratory Presentations52▾

Neurological Presentations83▾

Gastrointestinal Presentations74▾

Genitourinary and Reproductive Presentations48▾

Infectious Disease Presentations148▾

Trauma Presentations89▾

Toxicologic Presentations80▾

Psychiatric Presentations26▾

Musculoskeletal and Rheumatologic Presentations96▾

Dermatology Presentations23▾

Environmental and Exposure Presentations27▾

Hematologic and Oncologic Presentations36▾

Pediatric-Specific Presentations19▾

Endocrine and Metabolic Presentations45▾

ENT and Maxillofacial Presentations27▾

Ophthalmologic Presentations19▾

Obstetric Presentations23▾

Systemic and Miscellaneous Presentations17▾

Allergic Transfusion Reaction Anaphylaxis Angioedema Benedikt's Syndrome Cannabis-induced hyperemesis Eczema (acute flare)Gradenigo's Syndrome Horner's Syndrome (Acute)Huntington's Disease (Acute Presentation)Kanavel's Signs Lemierre's Syndrome Procedural sedation Radiation exposure Retained products of conception Sever's Disease Urticaria Venous air embolism

01Approach to the Critical Patient/attcp47

Immediate priorities

›Life-threatening acute presentations in HD

›Suicidal ideation or active attempt

›2 to 7 times higher suicide risk than general population

›Suicide accounts for 6.6% of HD deaths

›Immediate psychiatric evaluation and safety assessment

›Aspiration pneumonia

›Leading cause of death in HD

›Fever, tachypnea, hypoxia in patient with known dysphagia

›Immediate respiratory support and antibiotics

›Neuroleptic malignant syndrome

›Rigidity, hyperthermia, autonomic instability, altered mental status

›Risk with antipsychotics and tetrabenazine

›Discontinue offending agent immediately

›Sepsis from intercurrent infection

›UTI and pneumonia most common triggers

›Acute deterioration from baseline is not HD progression until infection excluded

›Broad spectrum antibiotics within 1 hour if septic shock

Stabilization and monitoring

›Airway and oxygenation

›SpO2 target >= 92% on supplemental oxygen

›NPO if dysphagia concern or aspiration event

›Escalate to definitive airway if unable to protect

›Hemodynamic monitoring targets

›SBP >= 90 mmHg

›MAP >= 65 mmHg

›Heart rate trending

›Continuous pulse oximetry

02History/hx53

Baseline and disease context

›Known HD diagnosis confirmation

›Genetic testing status and CAG repeat length

›Shoulson-Fahn Stage I through V and baseline functional capacity

›Treating neurologist and care team contacts

›Acute change from baseline characterization

›Tempo of deterioration (hours, days, weeks)

›New or worsening chorea, rigidity, gait instability

›Recent falls or head injuries

›Dysphagia progression or choking episodes

Psychiatric and cognitive symptoms

›Suicidal ideation screening

›Active plan, intent, means access

›Prior suicide attempts

›Depression history (65% lifetime prevalence in HD)

›Critical periods: pre-manifest and early symptomatic stages

›Behavioral symptoms

›Agitation and irritability

›Psychosis including delusions and hallucinations

›Disinhibition and aggression

›Apathy and functional withdrawal

›Obsessive-compulsive behaviors

›Cognitive trajectory

›Executive dysfunction progression

›New confusion or delirium onset

›Dementia severity baseline

Medication and treatment history

›Current medications

03Physical Exam/exam66

Vitals and general appearance

›Vital sign patterns in HD acute presentation

›Fever suggesting infection or NMS

›Tachycardia from dehydration, sepsis, or NMS

›Hypotension from dehydration or septic shock

›Tachypnea and hypoxia in aspiration pneumonia

›SpO2 on room air and response to supplemental oxygen

›General appearance

›Degree of chorea at rest and with activity

›Nutritional state and body habitus

›Evidence of falls or trauma

Neurological exam

›Chorea assessment

›Involuntary, irregular, purposeless movements flowing between body parts

›UHDRS Total Maximal Chorea score (0 to 28 scale)

›Distribution and severity change from baseline

›Dystonia and rigidity

›Particularly in advanced disease or juvenile HD variant

›Appendicular vs. axial involvement

›Oculomotor findings

›Impaired saccade initiation

›Slow or hypometric saccades

›Gaze fixation difficulty (present in up to 75%)

›Motor impersistence

›Inability to maintain tongue protrusion

›Milkmaid grip pattern on sustained handgrip

›Characteristic of HD

›Gait assessment

04Differential Diagnosis/ddx51

Life-threatening differentials

›Conditions requiring immediate action

›Neuroleptic malignant syndrome

›ICD-10 G21.0

›Rigidity, hyperthermia > 38.5 C, autonomic instability, altered mental status

›Antipsychotic or VMAT2 inhibitor exposure

›Aspiration pneumonia with sepsis

›ICD-10 J69.0

›Fever, hypoxia, infiltrate on imaging

›Sepsis from UTI or pneumonia

›ICD-10 A41.9

›Acute functional decline as presenting feature

›Subdural hematoma from fall

›ICD-10 S06.4

›Head trauma history, falls are common in HD

›New focal deficit or altered consciousness

›Rhabdomyolysis from severe chorea

›ICD-10 M62.82

›Elevated CK, myoglobinuria, renal failure risk

Chorea differentials for new or atypical presentations

›Chorea mimics requiring workup

›Tardive dyskinesia

›Antipsychotic exposure history

›Orobuccal predominance pattern

›Wilson disease

›Young patients without family history

›Kayser-Fleischer rings, low ceruloplasmin, hepatic dysfunction

›Sydenham chorea

05Laboratory Tests/lt39

Infection and metabolic workup

›Core laboratories for acute HD presentation

›Complete blood count

›Leukocytosis or leukopenia for infection

›Acanthocytes on peripheral smear if neuroacanthocytosis suspected

›Comprehensive metabolic panel

›Electrolytes and renal function for dehydration assessment

›Glucose (hyperglycemia can cause chorea)

›Hepatic function panel (Wilson disease, medication toxicity)

›Urinalysis and urine culture

›UTI is the most common acute deterioration trigger in HD

›Obtain even with mild or absent symptoms

›Blood cultures

›If febrile or sepsis suspected

›Prior to antibiotics when feasible

Targeted biomarkers

›Specific tests by clinical concern

›Creatine kinase

›Severe prolonged chorea and rhabdomyolysis concern

›Immobility and NMS workup

›Repeat every 6 to 12 hours if elevated

›TSH

›Thyrotoxicosis as cause of chorea

›New presentation without confirmed HD diagnosis

›Ceruloplasmin and serum copper

›Wilson disease in differential for young patients without family history

›Procalcitonin

›Bacterial infection support when sepsis suspected

06Diagnostic Tests/dt70

Scoring Systems

›HD-specific staging and severity tools

›Shoulson-Fahn Staging System (Stage I to V)

›Stage I: symptomatic, fully functional

›Stage II: 70 to 90% functional capacity

›Stage III: 50% functional capacity, independent living borderline

›Stage IV: less than 25% functional capacity, long-term care often needed

›Stage V: total functional dependence

›Unified Huntington Disease Rating Scale (UHDRS)

›Total Maximal Chorea score 0 to 28

›Behavioral and cognitive subscales

›Functional capacity assessment

›Standard clinical trial outcome measure

›Columbia Suicide Severity Rating Scale (C-SSRS)

›Recommended for HD suicidality assessment

›Distinguishes ideation from behavior

›Guides level of psychiatric intervention

›Total Functional Capacity (TFC) score

›0 to 13 scale integrated into UHDRS

›Decline correlates with disease stage

MRI

›Brain MRI indications in acute HD presentation

›Structural MRI with FLAIR and DWI

›New focal neurological deficit requiring stroke or hematoma exclusion

›Subdural hematoma after fall

›Rapid cognitive decline atypical for HD stage

›Characteristic HD MRI findings

›Caudate nucleus atrophy bilaterally

07Disposition/dispo42

Admission indications

›Criteria requiring hospital admission

›Active suicidal ideation or attempt

›Psychiatric admission required

›Secure environment with continuous monitoring

›Acute psychosis with aggression or inability for self-care

›Inpatient psychiatric or medical psychiatric unit

›Aspiration pneumonia or respiratory compromise

›Hypoxia requiring supplemental oxygen

›Inability to maintain oral intake

›Sepsis or serious intercurrent infection

›IV antibiotics and monitoring required

›NMS or suspected NMS

›ICU level monitoring and management

›Severe dehydration, rhabdomyolysis, or electrolyte derangements

›IV fluid resuscitation and serial labs

›Falls with significant injury

›Intracranial injury excluded by imaging

›Fracture or soft tissue injury requiring management

ICU and high acuity care

›ICU indications

›NMS with hemodynamic instability or hyperthermia

›Respiratory failure requiring intubation or HFNC

›Septic shock with vasopressor requirement

›Rhabdomyolysis with acute kidney injury

Observation indications

›Short-stay monitoring appropriate

›Mild dehydration responding to IV fluids

08Treatment/t116

Chorea management

›FDA-approved VMAT2 inhibitors for HD chorea

›Tetrabenazine

›Starting dose 12.5 mg orally daily

›Titrate by 12.5 mg per week based on response and tolerability

›Maximum 50 mg per day in CYP2D6 poor metabolizers

›Maximum 100 mg per day in extensive metabolizers

›Boxed warning for depression and suicidality

›Contraindicated in actively suicidal patients or untreated depression

›MAOI washout required: minimum 14 days

›Reserpine washout required: minimum 20 days

›Strong CYP2D6 inhibitors (fluoxetine, paroxetine) require dose reduction

›Maximum 50 mg per day with single dose maximum of 25 mg with CYP2D6 inhibitors

›Deutetrabenazine (Austedo)

›Better tolerability profile than tetrabenazine

›Common adverse effects: somnolence, dry mouth, diarrhea

›Similar boxed warning for depression and suicidality

›AAN guideline recommended for HD chorea

›Valbenazine (Ingrezza)

›Once-daily dosing

›Favorable tolerability profile

›QTc prolongation monitoring required

›Atypical antipsychotics for chorea with psychiatric comorbidity

›Olanzapine

›Dual benefit for chorea and behavioral symptoms

›Improvement in chorea, behavior, and irritability in Neuro-HD trial

›Starting dose 2.5 to 5 mg orally at bedtime

›Titrate weekly based on response

›Risperidone

›0.5 to 1 mg orally twice daily

›Titrate to effect

›Aripiprazole

›Lower metabolic side effect profile

›5 to 10 mg orally daily

Psychiatric emergency management

›Acute suicidality

›Safety assessment with C-SSRS

›Safe environment and continuous monitoring

›Psychiatric consultation for inpatient admission decision

›SSRIs for underlying depression

›First-line for HD depression

›Monitor closely for suicidality exacerbation

›If VMAT2 inhibitor is contributing to depression, dose reduce or discontinue

›Tetrabenazine contraindicated in actively suicidal patients

›Acute agitation and aggression

›De-escalation as first approach

›Benzodiazepines for acute agitation

›Lorazepam 1 to 2 mg IV or IM

›Titrate to calm, not sedation

›Use caution in respiratory compromise

›Haloperidol IV or IM for acute agitation if antipsychotic preferred

›2.5 to 5 mg IM or IV

›QTc monitoring

›Olanzapine IM for agitation

›5 to 10 mg IM

›Do not combine with IM benzodiazepine (respiratory depression risk)

›Evidence from ED agitation trials (Klein et al. 2018)

›Acute psychosis

›Atypical antipsychotics preferred over typical antipsychotics in HD

›Lower extrapyramidal side effect risk

›Delirium workup mandatory before attributing to HD

Neuroleptic malignant syndrome management

›NMS treatment protocol

›Immediately discontinue offending antipsychotic or tetrabenazine

›Aggressive IV fluid resuscitation

›250 to 500 mL NS bolus titrated to clinical response

›Active cooling for hyperthermia

›Target temperature < 38.5 C

›Dantrolene IV for severe hyperthermia and rigidity

›1 to 2.5 mg per kg IV bolus

›Repeat every 5 to 10 minutes to maximum 10 mg per kg per day

›Bromocriptine for dopaminergic restoration

›2.5 mg orally every 8 hours

›Titrate to response

›ICU transfer for hemodynamic monitoring and ventilatory support

Aspiration pneumonia treatment

›Respiratory support

›Supplemental oxygen titrated to SpO2 >= 92%

›HFNC for moderate to severe hypoxemia

›NPO until swallowing assessment completed

›Head of bed elevation to 30 to 45 degrees

›Antibiotic therapy for aspiration pneumonia

›Ampicillin-sulbactam IV

›3 g IV every 6 hours

›Renal dose adjustment when impaired

›Ceftriaxone IV plus metronidazole for aspiration flora

›Ceftriaxone 2 g IV every 24 hours

›Metronidazole 500 mg IV every 8 hours

›If severe beta-lactam allergy

›Levofloxacin 750 mg IV daily plus metronidazole 500 mg IV every 8 hours

›Dysphagia management during admission

›Speech-language pathology consult for formal swallowing assessment

›Modified texture diet based on assessment

›Thickened liquids as indicated

Supportive care and nutrition

›Hydration and nutrition

›IV fluid resuscitation for dehydration

›Normal saline or lactated Ringer's 250 to 500 mL bolus if hemodynamically indicated

›HD patients have significantly increased caloric requirements

›Hypermetabolism from continuous involuntary movements

›Nutritional consultation for supplementation

›PEG tube consideration in advanced disease with severe dysphagia

›Goals of care discussion required

›Palliative care involvement

›Constipation management

›Very common in HD and frequent acute trigger

›Polyethylene glycol 17 g orally daily

›Stimulant laxatives if bulk laxatives insufficient

›Disimpaction if severe obstipation

Medications to avoid or use with caution

›Contraindicated agents in HD

›L-dopa containing compounds

›May worsen chorea significantly

›MAOIs with tetrabenazine

›Minimum 14-day washout required

›Reserpine with tetrabenazine

›Minimum 20-day washout required

›Use with caution

›QTc-prolonging drugs with VMAT2 inhibitors

›Monitor QTc closely

›Strong CYP2D6 inhibitors (fluoxetine, paroxetine) with tetrabenazine

›Mandatory dose reduction to maximum 50 mg per day

09Special Populations/sp62

Pregnancy

›HD and pregnancy considerations

›Genetic counseling priority

›Autosomal dominant; 50% offspring transmission risk

›Pre-implantation genetic diagnosis available

›Prenatal testing options if parent is gene carrier

›Medication safety in pregnancy

›Tetrabenazine: limited safety data, use only if benefit outweighs risk

›Deutetrabenazine and valbenazine: insufficient human data

›SSRIs generally considered safer in pregnancy for depression management

›Benzodiazepines: use minimum effective dose, neonatal withdrawal risk

›Valproic acid: avoid due to teratogenicity

›Chorea management in pregnancy

›Multidisciplinary care with maternal-fetal medicine and neurology

›Non-pharmacologic strategies first (positioning, environmental modification)

›Aspiration risk increased in third trimester (delayed gastric emptying)

›Fetal monitoring

›Increased monitoring when viable gestation

›Maternal oxygenation target SpO2 >= 95% for fetal wellbeing

Geriatric

›Older adult HD considerations

›Late-onset HD

›Presentation after age 60 uncommon but recognized

›Shorter CAG repeats typical (36 to 39)

›May be mistaken for Parkinson disease or vascular dementia

›Medication sensitivity

›Renal dosing adjustment for VMAT2 inhibitors and antibiotics

›Higher QTc prolongation risk

10Background/b72

Epidemiology

›Prevalence and incidence

›Affects approximately 5 to 10 per 100,000 in populations of European descent

›Lower prevalence in Asian and African populations

›Autosomal dominant with complete penetrance at >= 40 CAG repeats

›Mean age of onset 35 to 45 years

›Median survival 15 to 20 years after symptom onset

›Cause-specific mortality

›Aspiration pneumonia is the leading cause of death

›Suicide accounts for 6.6% of HD deaths

›Suicide risk 2 to 7 times higher than general population

›Cardiovascular disease also a significant contributor

›Hospitalization epidemiology

›UTI and pneumonia are top hospitalization causes

›80.6% of hospitalized HD patients have Medicare or Medicaid

›60% of HD hospital admissions result in discharge to long-term care

›54.4% of all admissions result in LTCF placement

›11.1% of HD patients have at least one psychiatric hospitalization

›39% of psychiatric admissions associated with acute psychosis or aggression

›Psychiatric burden

›Depression: 65% lifetime prevalence

›Suicidal ideation: significant in pre-manifest and early symptomatic stages

›Psychosis: occurs in subset, more common in advanced disease

Pathophysiology

›Genetic mechanism

›CAG trinucleotide repeat expansion in HTT gene on chromosome 4p16.3

›Normal range < 36 repeats

›36 to 39 repeats: reduced penetrance

›>= 40 repeats: full penetrance

›>= 55 repeats: juvenile HD onset

›Longer repeats correlate with earlier onset

›Anticipation occurs particularly with paternal transmission

›Mutant huntingtin protein effects

›Abnormal polyglutamine expansion alters protein folding

›Toxic gain-of-function mechanism predominant

›Intranuclear and cytoplasmic aggregates form

›Disrupts transcription, mitochondrial function, and axonal transport

›Neurodegeneration pattern

›Preferential loss of medium spiny neurons in striatum (caudate and putamen)

›Caudate nucleus atrophy most prominent

›Cortical thinning in frontal and temporal regions

›Loss of indirect pathway neurons disrupts basal ganglia circuitry causing chorea

›Progressive dopaminergic system changes

›Motor symptom mechanism

›Early HD: loss of indirect pathway causes excess movement (chorea)

›Advanced HD: loss of direct pathway causes rigidity and bradykinesia

›Oculomotor circuit disruption explains saccade abnormalities

›Metabolic effects

›Hypermetabolism from continuous involuntary movements

›Weight loss progressive despite adequate caloric intake in some patients

›Mitochondrial dysfunction contributes to energy failure

Therapeutic Considerations

›Evidence base for chorea treatment

›AAN evidence-based guideline on pharmacologic treatment of HD chorea

›Tetrabenazine: Class I evidence for chorea suppression, Level A recommendation

›Deutetrabenazine: non-inferior to tetrabenazine with better tolerability

›Valbenazine: FDA-approved based on KINECT-HD trials

›Atypical antipsychotics: alternative when dual chorea and psychiatric benefit desired

›Neuro-HD trial: olanzapine, tetrabenazine, and tiapride compared; olanzapine showed improvements in chorea, behavior, and irritability

›Depression and suicidality treatment evidence

›SSRIs first-line for HD depression; limited HD-specific RCT data

›Suicidality peaks in early symptomatic and pre-manifest stages

›VMAT2 inhibitors carry boxed warning and are contraindicated with active suicidality

›Close monitoring required after any medication initiation or change

›Dysphagia management principles

›Speech-language pathology evaluation is standard of care

›Modified texture and thickened liquids reduce aspiration events

›100% of advanced-stage HD patients have dysphagia

›Supervised meals reduce aspiration events significantly

›PEG tube placement requires goals-of-care discussion

›Emerging and disease-modifying approaches

›Antisense oligonucleotides targeting mutant huntingtin under investigation

›Gene silencing approaches in clinical trials

›No currently approved disease-modifying therapy

›Enroll-HD observational registry informing natural history and biomarker data

11Patient Discharge Instructions/pdi39

copy discharge instructions

›Huntington's disease acute presentation home care instructions

›Take all prescribed medications exactly as directed

›Do not stop any medications without speaking to your neurologist or doctor first

›Abruptly stopping chorea medications or antipsychotics can cause serious problems

›Eating and drinking safety

›Only eat foods and liquids approved by your swallowing assessment

›Sit fully upright during all meals and for at least 30 minutes after

›Take small bites and sips; do not rush eating

›Have a caregiver or family member present during meals if possible

›Call your doctor before resuming any foods you were told to avoid

›Fall prevention

›Remove loose rugs and clutter from floors

›Use grab bars in bathroom and shower

›Wear non-slip footwear at home

›Do not walk alone if you have been falling frequently

›Mental health

›If you are having thoughts of hurting yourself, call 988 (Suicide and Crisis Lifeline) or go to the nearest emergency department immediately

›Continue all prescribed antidepressants and psychiatric medications

›Tell your care team about any mood changes, thoughts of self-harm, or unusual behaviors

›Warning signs to return to the emergency department

›Thoughts of suicide or self-harm

›Fever above 38.5 C (101.3 F)

›New or worsening confusion or agitation

›Trouble breathing or fast breathing at rest

›Difficulty swallowing or choking episodes

›Inability to eat or drink for more than 24 hours

›Muscle stiffness with fever (possible NMS)

12References/r33

Guidelines and key sources

›Clinical guidelines

›Armstrong MJ, Miyasaki JM. AAN Evidence-Based Guideline: Pharmacologic Treatment of Chorea in Huntington Disease. Neurology. 2012

›Nazarian DJ et al. ACEP Clinical Policy: Critical Issues in Diagnosis and Management of Adult Psychiatric Patient in the ED. Annals of Emergency Medicine. 2017

›Caron NS, Wright GEB, Hayden MR. Huntington Disease. GeneReviews. 2020

›Key references

›Roos RA. Huntington's Disease: A Clinical Review. Orphanet Journal of Rare Diseases. 2010

›Ross CA, Tabrizi SJ. Huntington's Disease: From Molecular Pathogenesis to Clinical Treatment. Lancet Neurology. 2011

›Walker FO. Huntington's Disease. Lancet. 2007

›Massey TH, McLauchlan DJ. Huntington's Disease: A Clinical Primer for Acute and General Physicians. Clinical Medicine. 2024

›Psychiatric and suicidality evidence

›Kachian ZR et al. Suicidal Ideation and Behavior in HD: Systematic Review and Recommendations. Journal of Affective Disorders. 2019

›Grimaldi A et al. Risk Factors and Interventions for Suicide in HD: Systematic Review. Journal of Clinical Medicine. 2024

›van Duijn E et al. Suicidal Ideation and Behavior per C-SSRS in HD Gene Expansion Carriers. Journal of Affective Disorders. 2018

›Stone F et al. Disentangling Suicidal Ideation from Behaviour in HD. General Hospital Psychiatry. 2026

›Shiino S et al. Characterization of Psychiatric Admissions in HD: Retrospective Review. Journal of Psychosomatic Research. 2025

›VMAT2 inhibitor evidence

›Baghaei A et al. Safety and Efficacy of VMAT2 Inhibitors in Huntington Disease: Systematic Review. Parkinsonism and Related Disorders. 2026

›Youssov K et al. Comparison of Tetrabenazine, Tiapride and Olanzapine in HD: Neuro-HD Trial. Parkinsonism and Related Disorders. 2025

›Rosenthal LS et al. Vesicular Monoamine Transport Inhibitors: Current Uses and Future Directions. Lancet. 2025

›Dysphagia and nutrition evidence

›Schindler A et al. FEES in Early-to-Advanced Stage HD. Scientific Reports. 2020

›Pizzorni N et al. Management of Dysphagia in HD: Descriptive Review. Neurological Sciences. 2020

›Kalkers K et al. Dysphagia, Fear of Choking, Preventive Measures in HD. Journal of Nutrition Health and Aging. 2022

›Pizzorni N et al. Predictors of Malnutrition Risk in Neurodegenerative Diseases. European Journal of Neurology. 2022

›Hospitalization and epidemiology

›Dubinsky RM. No Going Home for Hospitalized HD Patients. Movement Disorders. 2005

›Rocha NP et al. Clinical Correlates of Depression and Suicidality in HD: Enroll-HD Analysis. Cognitive and Behavioral Neurology. 2022

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Reviewed by SymptomDx Medical Team · Last reviewed August 18, 2026

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