Pure sensory syndrome: symptoms, causes and treatment

This syndrome may occur after a lacunar infarction that damages the inside of the brain.

Pure sensory syndrome occurs after a cerebral infarction in the thalamus, a vital structure for filtering sensory information.This is a structure of vital importance for filtering sensory information, and causes, among other symptoms, paralysis and a loss of sensitivity in half of the body.

In this article we explain what pure sensory syndrome is, what are its main causes, what symptoms it causes and what is the treatment to follow.

What is pure sensory syndrome?

Pure sensory syndrome is one of the classic lacunar syndromes best defined by the physician Charles M. Fisher.one of the first neurologists to study and contribute to the understanding of cerebrovascular accidents, especially those related to carotid artery diseases and lacunar infarcts.

In clinical practice, lacunar syndrome is understood as any clinical manifestation in which a lacunar cerebral infarction occurs.

This type of infarction are characterized by the presence of tiny lesions (no larger than 15 mm in diameter). (no larger than 15 mm in diameter) caused by the occlusion of small branches of the perforating arteries of the brain.

Pure sensory syndrome constitutes 7% of lacunar infarcts and sufferers manifest persistent or transient sensory symptoms affecting half of the body.

Causes

Little is known about the frequency with which the different forms of the syndrome occur.These include: complete hemisensory syndrome (with sensory involvement encompassing the entire facial-brachio-crural axis, i.e., the face, arm and leg on one side of the body); and incomplete hemisensory syndrome (less specific and with different clinical variants).

The most common cause of pure sensory syndrome includes lacunar infarction in the thalamus, although it can also be secondary to intracerebral hemorrhages or to a cortical, internal capsule, parietal, mesencephalic or pontine lesion (related to the pons, a structure located at the base of the brain).

There is not yet much information regarding the different types of lacunar infarcts that can cause pure sensory syndrome, as well as the differences between lacunar and non-lacunar strokes.

Nevertheless, studies suggest that in 80-90% of cases, the cause of the pure sensory syndrome is lacunar infarctIn the remaining 10% of cases, the causes are varied, including atherothrombotic infarcts, primary intracerebral hemorrhages and other types of infarcts of unknown etiology.

Symptoms

Pure sensory syndrome causes a series of sensory symptoms that usually affect the face, arm and leg on one side of the body (hemi-hypoesthesia of the face, arm and leg on one side of the body). (facial-brachio-crural hemi-hypoesthesia).

Common symptoms include: isolated hypoesthesia (reduced sensation) without motor involvement, paralysis of one side of the body, or hemiplegia.The syndrome is characterized by dysarthria (difficulty in articulating sounds and words), nystagmus (uncontrollable and involuntary movement of the eyes) and visual or cognitive defects (alterations in executive functions, such as semantic fluency or verbal short-term memory).

This lacunar syndrome can also be may also be associated with neuropathic type of painEpicritical sensitivity (which allows discriminating both the quality and the location of a sensory stimulus), protopathic sensitivity (opposite to epicritical sensitivity) or both may be affected.

Other types of symptoms such as paresthesias (numbness and tingling in the body, mainly the extremities) are usually infrequent, as is isolated proprioceptive loss, which involves the ability to know the relative position of the body and muscles at all times.

Hypoesthesia occurring in pure sensory syndrome may be faciobrachial, faciobrachio-crural, faciocrural or truncal and crural, with frequent thalamic topography, and that occurring in the fingers may be associated with parietal cortical lesions.. Other patterns with this same symptom have also been associated with brainstem lesions.

Treatment

One of the maxims when treating pure sensory syndrome and, in general, any type of lacunar infarction, is to early intervention. This means that treatment must be urgent, as the first hours after the stroke are crucial, and a difference of hours may mean that the patient will survive or not.

After the stroke, the person should be taken to the nearest hospital as soon as possible. to start treatment as soon as possible (within the first 3 hours after the injury), usually using anticoagulant drugs to eliminate the occlusion and allow the Blood supply to flow normally again. Occasionally brain surgery is required, but this is not common.

Once the operation has been performed, the patient will have to begin a rehabilitation that includes visits to different professionals of several sanitary branches.

Physiotherapy and medical follow-up

The role of the physiotherapist is to help the patient restore motor functions, mainly by performing exercises with the affected joints. The professional must take special care not to generate major complications in the patient's body and limbs, which will be very weakened after the infarction.

For his part, the specialist physician (the neurologist, in this case) will be in charge of monitoring possible neurological complications and may request any type of test required (a CAT scan, MRI, etc.).

Neuropsychological rehabilitation

The role of the neuropsychologist in these cases is to rehabilitate the higher cognitive functions that have been affected.. In lacunar infarcts, for example, executive functions, which are responsible for planning, reviewing and evaluating complex information that helps the individual to adapt to the environment and achieve goals effectively, may be affected.

The neuropsychologist, through the application of individualized programs and the performance of specific tasks, will help the patient to restore and/or compensate for the cognitive deficits caused by the injury, so that the person regains his autonomy and can become functional again in all areas of his life (family, work and socially).

Occupational and psychological therapy

The main objective of occupational therapy is enable the patient to participate in activities of daily living.. The work of the occupational therapist is to facilitate that the individual, after the recovery period, is able to modify his or her environment so that he or she can participate in social and community activities again.

Psychological therapy will help the patient to improve the skills that have been impaired and to recover from the damage at the affective level. that a disorder of this type causes in the patient and his or her closest environment. The psychologist must provide the patient with the necessary tools to achieve the psychological well-being and vital balance that everyone needs after a process like this.

Bibliographical references:

• Arboix, A., García-Plata, C., García-Eroles, L., Massons, J., Comes, E., Oliveres, M., & Targa, C. (2005). Clinical study of 99 patients with pure sensory stroke. Journal of neurology, 252(2), 156 - 162.
• Fisher CM (1965) Pure sensory stroke involving face, arm and leg. Neurology 65:76 - 80.
• Grau-Olivares, M., Arboix, A., Bartrés-Faz, D., & Junqué, C. (2004). Neuropsychological alterations in lacunar-type cerebral infarcts. Mapfre Medicina, 15(4), 244 - 250.