Pupillary disorders and areflexia

When the pupil disorders are detected in the form of changes in the width, shape of the pupils, their response to light and convergence with accommodation, combined with the loss of deep reflexes from the extremities (at least Achilles reflexes), there is usually a suspicion of neurosyphilis. However, there are at least four other pathological conditions that should be borne in mind in the presence of this clinical picture.

[1], [2], [3], [4], [5], [6], [7]

The main causes of pupillary disorders:

1. Eddie Syndrome.
2. Spinal dorsalis (Tabes dorsalis).
3. Diabetic polyneuropathy.
4. Combined degeneration of the spinal cord (funicular myelosis).

Eddie Syndrome

Complete Eddie syndrome includes: moderate dilatation of the pupils with an almost total lack of light response or for accommodation with convergence and the absence of achilles reflexes. Sometimes knee reflexes also drop out, in rare cases there is complete areflexia. Sensitive disturbances are not present, speeds of carrying out on impellent and sensitive nerves are not changed. The patient complains about the blinding effect of bright light (sun) and on the blurriness of the image when examining small objects at close range. On examination, there is a lack of phasic narrowing of the pupils during their direct illumination and in convergence with accommodation. A pharmacological test is needed to confirm the parasympathetic denervation hypersensitivity of the involved muscle (the muscle that narrows the pupil).

There is disagreement as to whether to call this condition a disease. Except for the above symptoms, the condition does not do any harm to the patient, and there are no other symptoms or painful manifestations. Eddie's syndrome does not require treatment, except for the recommendation to wear sunglasses.

Partial variants of Eddie's syndrome (pupil disorders without areflexia, areflexia without pupillary disorders) are described. There are hereditary forms of the Edie syndrome.

To exclude neurosyphilis, negative serological results are sufficient.

Spinal dorsalis (Tabes dorsalis)

In spinal cord, the affected pupil is reduced in diameter and has an irregular shape. With the complete absence of the reaction of this pupil to light, the reactions to accommodation and convergence are completely preserved (the pupil of Ardzhil-Robertson). Another difference from Eddie's syndrome is, as a rule, the involvement of both eyes. Aryflexia is combined with a variety of disorders in the sensitive area - from a violation of deep sensitivity and a sense of posture manifested in the form of dynamic sensitized ataxia (increased ataxia when walking without vision control), to disturb the vibration and pain sensitivity. Painful stimuli are often perceived with considerable delay. Speed of conduction on nerves is not changed.

Diabetic polyneuropathy

The most common form of peripheral nerve pathology is diabetic polyneuropathy. The absence of achilles reflexes and a decrease in vibration sensitivity - even in patients who do not make any complaints about impaired motor and sensitive functions - is a very common phenomenon. Often, the autonomic nervous system is involved; a clinical sign of her suffering is often the narrowing of the pupils and the slow, incomplete reaction to light and accommodation with convergence, which distinguishes these pupil disorders from the symptom of Argyll-Robertson. There are always discrepancies in the study of nerve conduction velocities-a reduction in the speed of movement along motor and (or) sensitive fibers. The degree of severity of possible deviations in the study of evoked potentials is determined by the degree of interest of the peripheral nerves.

Combined degeneration of the spinal cord (funicular myelosis)

In the context of this chapter, the most interesting are those 50% of patients with vitamin B12 deficiency, which do not cause Achilles reflexes. Typical complaints are complaints of paresthesia and a violation of those types of sensitivity that are mediated by the posterior columns of the spinal cord.

Often there is a narrowing of both pupils with preservation of their photoreactions. When studying the rates of conduction along the nerves, a delay in the excitation of motor and sensitive fibers is revealed. The degree of severity of deviations detected during registration of somatosensory evoked potentials and reflecting the interest of the posterior columns is significantly greater than that which could be attributed to the involvement of peripheral nerves. This, in particular, applies to the evoked potentials from the anterior-tibial and gastrocnemius nerves. Naturally, serological tests for the presence of syphilitic infection are negative.

Diagnosis does not cause difficulties when there are signs of a paresis of the extensor of the foot; this is observed in about 50% of cases. It is clear that for positive diagnosis it is necessary to prove a violation of absorption of vitamin B12 in the intestine.