From the Guidelines
Hyperreflexia syndrome is a condition characterized by overactive or exaggerated reflexes, which can be observed in patients with hepatic encephalopathy (HE), particularly in noncomatose patients, as noted in the 2014 practice guideline by the American Association for the Study of Liver Diseases and the European Association for the Study of the Liver 1. In the context of HE, hyperreflexia can be accompanied by other motor system abnormalities, such as hypertonia and a positive Babinski sign. It is essential to recognize that hyperreflexia in HE patients may not always be a prominent feature, as the mental and motor signs of the condition can vary greatly between individuals. Some key points to consider about hyperreflexia syndrome in HE patients include:
- Hyperreflexia can be a part of the clinical presentation of HE, which also includes alterations in consciousness, personality changes, and sleep disturbances 1.
- The presence of hyperreflexia, along with other motor system abnormalities, can indicate the progression of HE and the need for prompt medical attention.
- Hepatic myelopathy (HM), a particular pattern of HE, can also present with severe motor abnormalities, including hyperreflexia, and may not respond to standard therapy 1.
- The reversibility of hyperreflexia and other manifestations of HE is still a topic of debate, with some research suggesting that certain mental deficits may persist even after treatment 1.
From the Research
Definition and Overview of Hyperreflexia Syndrome
- Hyperreflexia syndrome, also known as autonomic dysreflexia/hyperreflexia, is a life-threatening condition characterized by generalized sympathetic hyperactivity and paroxysmal hypertension 2, 3.
- It is often found in quadriplegics and high paraplegics, and can be precipitated by distension of hollow viscus, usually the bladder 3.
- The syndrome has been referred to by various names in the literature, including sympathetic hyperreflexia, paroxysmal hypertension, spinal poikilopiesis, autonomic spasticity, paroxysmal hyperactive autonomic reflexes, and paroxysmal neurogenic hypertension 2.
Clinical Presentation and Diagnosis
- Hyperreflexia can manifest as exaggerated tendon reflexes with abnormal reflex spread to other segments, and can be associated with spasticity, spastic dystonia, and soft tissue stiffness 4.
- In some cases, hyperreflexia can be a feature of Guillain-Barré syndrome, particularly in the acute motor axonal neuropathy (AMAN) form 5, 6.
- Electrophysiological studies may show high soleus maximal H-reflex amplitude to maximal compound muscle action potential amplitude ratio, suggestive of spinal motoneuron hyperexcitability 6.
Treatment and Management
- Treatment of hyperreflexia syndrome is directed at removing the offending stimulus, such as relieving bladder distension 3.
- In some cases, parenteral drug therapy may be required to abort the symptoms 3.
- Plasmapheresis has been used to treat hyperreflexia in patients with Guillain-Barré syndrome, resulting in rapid recovery 5.