Tethered medullary symptoms

The symptoms of the patient with an anchored medulla or lumbosacral lipoma are variable and depend largely on the age of presentation and the severity of the malformation. At younger ages, lipomas are diagnosed primarily by cutaneous stigmata, whereas in older patients the symptoms are usually neurological, as cutaneous lesions may go unnoticed or be underdiagnosed until the first symptoms arise.

  • Cutaneous signs: The main cutaneous stigmata associated with lumbosacral lipomas are: a mass in the lumbar region, hirsutism (abnormal tufts of hair), dimples (dermal sinuses), coccygeal appendages (“human tails” or “tails”) and/or capillary hemangiomas (vascular spots or “cravings”).

Almost 90% of patients with a lipoma present with at least one cutaneous manifestation, and most present with several of these. The most frequent cutaneous stigma associated with a lipoma is the subcutaneous mass, consisting of a soft lump over the dysraphism, which may be slightly asymmetric and lateral, and which deflects the gluteal fold.

The sacral pit is a very frequent finding that must be differentiated from the dermal sinus. The former are located above the coccyx, in the midline within the intergluteal fold. Although lipomas associated with sacral pits have been described, this association is infrequent, and in the absence of other signs it is not necessary to perform complementary studies.

  • Sensory-motor alterations: Although at birth many of the children are asymptomatic, it is accepted that the natural history of this malformation is towards a progressive deterioration, and this constitutes the main reason for its surgical indication when an anchored medulla is associated. First and second motor neuron deficits may be found in the same affected limb, and progressive weakness with patchy alterations of sensibility is a common finding in the evolution of these patients.
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As a consequence of this neurological involvement, orthopedic deformities are an early sign, and often the first warning sign of deterioration. Due to an imbalance in the innervation of opposing muscle groups, up to one third of patients have club feet, joint deformities and dislocations, and shortening of the length of the feet or limbs. Scoliosis is present in 10% of patients and is progressive in case of spinal anchorage. Continued evaluation of scoliotic curves is recommended, which usually stop or reverse after unanchoring surgery.

  • Sphincteric disturbances: Impaired urological function is the most common neurological disturbance in patients with complex lipomas, affecting up to 50% of patients. It can manifest in the form of recurrent urinary tract infections, incontinence or incomplete bladder emptying resulting in vesicoureteral reflux and chronic renal failure due to renal parenchymal impairment. Its detection correlates with the age of the patient (it is easier to recognize in older patients, who should have developed complete continence) and with the sensitivity of the diagnostic tools used. Often an altered urodynamic study may be the only abnormality present.

If detected very early in younger children, the bladder abnormality may be reversible, but in older children and adults improvement after surgery beyond stabilization of the lesion is rarely achieved. The appearance of urological symptomatology may be the first symptom of reanchorism in a patient who has previously undergone surgery for spinal dysraphism.

The alteration of fecal continence due to hypotonia of the anal sphincter is less frequent, but most patients present some degree of constipation, which in the most severe degrees can produce overflow incontinence.

  • Pain: It is the exception in younger children, but older children and young adults frequently present lumbar pain, with erratic irradiation to the lower extremities. Characteristically, the pain worsens with exercise, stretching maneuvers, or trauma.