Autoimmune encephalitis comprises a group of conditions characterized by inflammation of the brain due to autoimmune mechanisms, leading to neurological and psychiatric manifestations.

Key Points

• Increasing recognition in past decade
• Can be paraneoplastic or non-paraneoplastic
• Affects both children and adults
• Early treatment improves outcomes
• Multiple antibody types identified

Classification

• By Location
• Limbic encephalitis
• Brainstem encephalitis
• Cerebellitis
• Pan-encephalitis
• By Antibody Type
• Cell-surface antibodies
• Intracellular antibodies
• Synaptic antibodies

Clinical Manifestations

General Symptoms

• Cognitive Changes
• Working memory deficits
• Short-term memory loss
• Confusion
• Language dysfunction
• Psychiatric Symptoms
• Psychosis
• Anxiety
• Depression
• Personality changes
• Agitation
• Neurological Signs
• Seizures
• Movement disorders
• Autonomic instability
• Decreased consciousness

Limbic Encephalitis-Specific Features

• Core Symptoms
• Anterograde amnesia
• Behavioral changes
• Temporal lobe seizures
• Emotional lability
• Associated Features
• Sleep disturbances
• Hypothalamic dysfunction
• Autonomic instability

Red Flags

• Rapid progression
• Status epilepticus
• Autonomic instability
• Decreased level of consciousness
• New-onset psychosis

Diagnostic Approach

Initial Evaluation

• Clinical Assessment
• Detailed neurological examination
• Psychiatric evaluation
• Cognitive testing
• Autonomic assessment
• Laboratory Studies
• CSF analysis
• Serum antibody panels
• Inflammatory markers
• Metabolic workup

Imaging Studies

• MRI Brain
• T2/FLAIR hyperintensity in temporal lobes
• Contrast enhancement
• Volumetric changes
• Hippocampal involvement
• FDG-PET
• Hypermetabolism in acute phase
• Hypometabolism in chronic phase

Key Antibody Testing

• Cell Surface Antibodies
• Anti-NMDA receptor
• Anti-AMPA receptor
• Anti-LGI1
• Anti-CASPR2
• Anti-GABA(B) receptor
• Intracellular Antibodies
• Anti-Hu
• Anti-Ma2
• Anti-GAD65

Treatment Strategies

First-Line Therapy

• Immunotherapy
• High-dose corticosteroids
• IVIG
• Plasmapheresis
• Supportive Care
• Seizure management
• Psychiatric support
• ICU care if needed

Second-Line Therapy

• Rituximab
• Cyclophosphamide
• Mycophenolate mofetil
• Azathioprine

Tumor Treatment

• Tumor screening
• Tumor removal if present
• Oncologic therapy
• Regular surveillance

Symptomatic Treatment

• Antiepileptic drugs
• Antipsychotics
• Anxiolytics
• Sleep medications

Disease Subtypes

Anti-NMDA Receptor Encephalitis

• Clinical Features
• Psychiatric symptoms predominant
• Movement disorders
• Autonomic instability
• Often paraneoplastic

LGI1 Encephalitis

• Characteristics
• Faciobrachial dystonic seizures
• Hyponatremia
• Memory impairment
• Better prognosis

CASPR2 Encephalitis

• Features
• Neuromyotonia
• Neuropathic pain
• Cognitive changes
• Autonomic dysfunction

Monitoring & Prognosis

Follow-up Assessments

• Clinical Monitoring
• Neurological examination
• Cognitive assessment
• Psychiatric evaluation
• Quality of life measures
• Laboratory Monitoring
• Antibody titers
• Inflammatory markers
• Treatment-related monitoring

Prognostic Factors

• Favorable Factors
• Early treatment
• Cell-surface antibodies
• No underlying malignancy
• Good initial response
• Poor Prognostic Factors
• Delayed treatment
• Intracellular antibodies
• Status epilepticus
• ICU admission

Long-term Outcomes

• Recovery Patterns
• Complete recovery (30-50%)
• Mild deficits (30-40%)
• Severe deficits (10-20%)
• Mortality (5-10%)
• Rehabilitation Needs
• Cognitive rehabilitation
• Physical therapy
• Occupational therapy
• Psychological support