Autoimmune encephalitis (AE) encompasses a group of conditions where the immune system attacks the brain -- most commonly via antibodies against neuronal surface antigens (NMDAR, LGI1, CASPR2, AMPA, GABA-B) or intracellular antigens (Hu, Yo, Ri, amphiphysin). The clinical presentation is highly variable but typically includes a subacute onset of psychiatric symptoms, cognitive impairment, seizures, and movement disorder. Motor manifestations that affect walking -- ataxia, dystonia, hyperkinesia, or encephalopathy-related gait impairment -- are common in the acute phase.
AE Motor Features Affecting Walking
- Ataxia: Cerebellar involvement (particularly in anti-CASPR2, anti-amphiphysin, and paraneoplastic AE) produces gait ataxia with wide-base, unsteady walking
- Dystonia: Involuntary muscle contractions affecting limb position during walking (faciobrachial dystonic seizures in anti-LGI1; generalised dystonia in other subtypes)
- Encephalopathic gait: The confused, disorganised gait of acute encephalopathy -- the person is not neurologically processing walking tasks normally and may wander unpredictably
- Orofacial dyskinesia: Abnormal face and jaw movements -- not directly affecting walking, but a marker of NMDAR-AE severity
AE Cane Use: The Acute and Recovery Phase Distinction
Autoimmune encephalitis is typically a reversible condition if treated promptly (immunotherapy: corticosteroids, IVIG, plasmapheresis, and in refractory cases rituximab or cyclophosphamide). The walking aid requirements change dramatically between the acute phase and recovery:
- Acute phase: The confusion and behavioural disturbance of AE makes unsupervised cane use unsafe. A person with AE may not understand how to use a cane correctly. Supervised walking with a frame or bilateral support is more appropriate
- Recovery phase: As immunotherapy takes effect and cognitive function returns, gait ataxia or residual weakness may persist. This is the phase where a cane becomes appropriate -- as an aid to residual ataxia or weakness during the recovery trajectory
- Residual deficits: In a minority of patients, AE produces permanent neurological deficits. Long-term cane use follows the same principles as for the underlying motor deficit (ataxia, spasticity, weakness)
Paraneoplastic AE: Cancer Context
In paraneoplastic AE, the encephalitis is triggered by an underlying cancer (typically small cell lung, ovarian, or breast). The neurological deficits may be irreversible if the underlying tumour is not treated. Paraneoplastic ataxia (anti-Yo, anti-Hu) in particular may cause permanent cerebellar damage, and long-term walking aid use follows ataxia management principles.
AE Phase and Walking Aid
| AE Phase | Walking Status | Appropriate Aid |
|---|---|---|
| Acute (confused, behavioural) | Unsafe unsupervised walking | Supervised bilateral support; frame; no independent cane |
| Sub-acute recovery (improving) | Residual ataxia or weakness; improving cognition | Cane as cognition recovers and supervised use becomes safe |
| Recovery (residual deficits) | Community ambulation with motor deficit | Cane per specific residual deficit (ataxia, weakness) |
| Paraneoplastic permanent deficit | Permanent cerebellar or motor deficit | Long-term cane; as per ataxia or SCI principles |
Related: Walking Cane for Ataxia. Explore DaiWalk walking canes.
