Hypoesthesia

Hypoesthesia in spinal cord tumors

During spinal cord compression by neoplasms, sensory disorders develop gradually. The structure of the symptom complex depends on the localization and growth type of the tumor. Two main types of disorders are distinguished:

1. Radicular disorders. Hypoesthesia occurs along the path of the affected nerve root. It is often accompanied by radicular pain (worsening when lying down and coughing), paresthesia, and hyperalgesia.
2. Tract disorders. Characterized by a decrease in sensitivity strictly below the level of the lesion.

Topical diagnosis directly relies on the area of hypoesthesia:

• Cervical region: tract disorders involve both the arms and legs.
• Thoracic region: disorders are detected only in the lower extremities.
• Lumbar region: numbness is localized in the distal parts of the legs.
• Conus medullaris (segments SIII–SV): specific anesthesia occurs in the anogenital area, combined with pelvic dysfunction.
• Lateral localization (Brown-Séquard syndrome): deep sensation is lost on the side of the tumor, while pain and temperature sensation are lost on the opposite (contralateral) side.

Clinical example: In a female patient with epidural lymphoma at the Th10 level, hypoesthesia developed in a specific manner. Starting from the inner surface of the thighs, it spread downward and then extended upward onto the trunk. At the same time, tactile and pressure senses were impaired significantly more than protopathic sensitivity.

Sensory disorders in osteochondrosis

In degenerative changes of the intervertebral discs (especially with generalized osteochondrosis), hypoesthesia has a pronounced segmental-radicular character.

• Zones of decreased pain and tactile sensitivity are located in the form of longitudinal strips involving the gluteal region, thigh, lower leg, and foot.
• The decrease in sensitivity often alternates with hyperesthesia (the sensation of "crawling ants" and tingling).
• The symptoms are accompanied by an antalgic posture (a forced tilt of the trunk with weight shifted to the healthy leg), a stiff gait, and sharply positive tension signs (Lasegue's sign and Bechterew's crossed sign).
• Autonomic disorders are frequently detected in the zones of hypoesthesia: dryness and peeling of the skin, cyanosis, and local sweating abnormalities.

Central hypoesthesia and thalamic syndrome

Damage to brain structures (e.g., hemorrhage in the area of the basal ganglia and thalamus) causes a complex cascade of sensory disorders on the side of the body opposite to the lesion.

In the acute period, patients exhibit:

• Hypoesthesia and hypalgesia near the midline.
• Pallanesthesia — complete loss of vibratory sense.
• Minor proprioception disorder against the background of central hemiparesis.

Several months later (during the formation of a residual cyst in the thalamus), the motor deficit may regress, but a severe pain syndrome forms at the site of the former hypoesthesia. Patients begin to experience paroxysms of pain and dysesthesia, which are subjectively compared to electric shocks. It is extremely difficult to manage such conditions; a prolonged combination of anticonvulsants and antidepressants (e.g., carbamazepine and amitriptyline) is usually required.

Class and exam questions

What else to study on this topic

• Differential MRI diagnosis of intramedullary and extramedullary tumors
• Tension signs: biomechanics of Lasegue's and Bechterew's signs
• Autonomic and visceral disorders in cauda equina compression
• Anatomy of the epithalamus: habenular nuclei and pineal gland physiology
• Pathogenesis of post-stroke thalamic pain formation

Other topics in the section "DeMyer's The Neurologic Examination" / "Duus' Topical Diagnosis in Neurology"

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