How are reflexes affected in patients with hepatic encephalopathy?

Reflex Abnormalities in Hepatic Encephalopathy

In patients with hepatic encephalopathy, reflexes show a variable pattern with both hyper-reflexia and diminished reflexes possible, depending on the stage of encephalopathy and specific clinical presentation. 1

Characteristic Reflex Patterns

• In non-comatose patients with hepatic encephalopathy, motor system abnormalities often include hypertonia, hyper-reflexia, and a positive Babinski sign 1
• As encephalopathy progresses to coma, deep tendon reflexes may diminish and even disappear, although pyramidal signs can still be observed 1
• The presentation of reflexes is not uniform and may not progress in parallel with mental status changes, creating difficulties in staging the severity of HE 1

Special Clinical Presentations

• Hepatic myelopathy (HM) presents with a distinct pattern characterized by:

  • Progressive spasticity and weakness of lower limbs with hyper-reflexia 1
  • Relatively mild persistent or recurrent mental alterations 1
  • Poor response to standard ammonia-lowering therapy 1
  • Potential reversal with liver transplantation 1, 2

• Cirrhosis-associated parkinsonism may present with:

  • Prominent extrapyramidal and/or pyramidal signs 1
  • Unresponsiveness to ammonia-lowering therapy 1
  • Occurs in approximately 4% of patients with advanced liver disease 1

Asterixis and Motor Manifestations

• Asterixis ("flapping tremor") is often present in early to middle stages of HE before stupor or coma 1, 2
• It is not actually a tremor but a negative myoclonus consisting of loss of postural tone 1, 2
• Easily elicited by actions requiring postural tone, such as hyperextension of the wrists with separated fingers 1
• Can be observed in various body areas including feet, legs, arms, tongue, and eyelids 1, 2
• Not pathognomonic of HE as it can be observed in other conditions like uremia 1

Other Motor Abnormalities

• Extrapyramidal dysfunction is common, including:

  • Hypomimia, muscular rigidity, bradykinesia, hypokinesia 1
  • Monotony and slowness of speech 1
  • Parkinsonian-like tremor 1
  • Dyskinesia with diminished voluntary movements 1

• Involuntary movements similar to tics or chorea occur rarely 1

• Transient focal neurological deficits can occur rarely 1

• Seizures are very rarely reported in HE 1

Clinical Implications

• The variable presentation of reflexes makes it challenging to use them alone for staging HE severity 1
• Persistent hyper-reflexia with minimal mental status changes may indicate hepatic myelopathy rather than typical HE 1, 2
• The presence of both pyramidal signs (like hyper-reflexia) and extrapyramidal dysfunction should raise suspicion for more severe or chronic forms of HE 1
• Monitoring reflex changes can help in assessing progression or improvement of HE, but should be interpreted alongside mental status changes 1