What is Tetraparesis?

Oct 19, 2018

Tetraparesis, or quadraparesis, is a condition in which all four limbs are weak. Several causes exist, many of which are treatable.

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In some patients with tetraparesis, the limbs may lack voluntary motor control, while in other patients, some limbs or parts of limbs may be paralyzed but others function normally. The cause of the weakness is a partial interruption of the nerve impulses passing along the spinal cord, hence the muscles supplied by these nerves do not function normally.

A full neurologic examination is thus essential to identify the pattern of weakness and the involved nerves. This will usually be followed by imaging studies to locate the area of damage causing the sensory and motor weakness. This, in turn, will determine the treatment approach.

Causes

Congenital tetraparesis

Some patients have tetraparesis due to congenital or birth problems. Among these, cerebral palsy (or spastic tetraparesis) is the most common reason.

Acquired tetraparesis

Spastic tetraparesis may also result from neurologic degeneration
Spinal trauma leading to cord damage, as in intervertebral disc rupture, a fall, or a motor accident
Acute myopathies
Conversion disorders and locked-in syndrome
Evolving flaccid paralysis may occur due to myelopathies involving the spinal cord itself or peripheral nerves.
Evolving flaccid paralysis due to neuropathies

Causes of tetraparesis which affect the spinal cord include:

Cord compression by a bulging or ruptured intervertebral disc, tumor, hematoma, abscess or other mass lesion, or stenosis of the spinal column
Transverse myelitis affecting the whole of one transverse section of the cord
Encephalitis involving the brainstem
Necrotizing myelopathy
Infections such as polio, enterovirus or flavivirus infections

Neuropathies which can cause evolving flaccid paralysis include:

Guillain-Barre syndrome and its variants
Secondary neuropathies due to metabolic dysfunctions as in diabetes, porphyria, Lyme disease, uremia, some poisonings, autoimmune vasculitides, paraneoplastic syndromes and critical illnesses
Neuromuscular junction diseases such as myasthenia gravis, botulism, some envenomations

Symptoms and signs

The presence of acute hypotonia and hypo- or areflexia along with tetraparesis may signal a lesion or involvement of the lower central nervous system, i.e., the spinal cord.

The presence of spastic muscles and high muscle tone shows upper motor neuron involvement, i.e., of the brain. In cerebral palsy, both upper and lower limbs are symmetrically and intensely affected with a floppy neck, dysarthria and respiratory difficulties in severe cases.

The occurrence of rapidly progressing tetraparesis may signal other conditions. In most cases, it is ascending upwards from the lower limbs, but it may sometimes be a descending weakness. The reflexes are affected early in peripheral neuropathies, but are typically spared in diseases of the neuromuscular junctions and in myopathies until severe weakness begins to appear.

In most cases, the patient finally presents with severe muscle weakness, poor or absent deep tendon reflexes, and in some cases, involvement of the respiratory, brainstem and ocular muscles. Symmetry of paralysis, the involvement of extraocular muscles, sensory signs, and autonomic nervous system involvement are commonly seen.

The clinical features along with some diagnostic neurological and electromyographic (EMG) tests help to confirm the condition. Serum electrolytes, serum creatine kinase, and cerebrospinal fluid (CSF) studies are all useful in differentiating various conditions, as are muscle and nerve function testing such as the nerve conduction studies and EMG testing.

Management of tetraparesis

Once the underlying cause and extent of nerve damage is identified, various methods of treatment may be employed, such as: