Are herniated cerebellar tonsils the main culprit of chiari malformation type i symptoms? brainstem compression hypothesis seems to be re-elucidated and revised

İngilizce (OpenAlex)

neurological deficits including motor weakness, sensory disturbances and urinary or stool incontinence (2).The demonstration of TCS is based on the magnetic resonance imaging (MRI) findings such as thick filum terminale (>2 mm diameter), a low-positioned conus medullaris, posterior displacement of the conus medullaris and filum terminale, and a wide lumbar and sacral subarachnoid space (18).However, if there is no anatomical evidence of low-lying conus on lumbar MRI and the filum terminale has normal thickness, it is difficult to diagnose tethered spinal cord.In such cases, after a somatosensory evoked potentials study, sectioning of filum terminale in case of a tethered cord diagnosis often helps resolve the symptoms but the indications for cutting the filum in this context are still controversial (6,14). █ INTRODuCTION The Chiari malformation I (CM I) is a disorder that has been defined as downward herniation of the cerebellar tonsils at least 5 mm or greater through the foramen magnum which is a leading cause of syringomyelia and occurs in association with osseous abnormalities at the craniovertebral junction (8).In CM I, posterior fossa decompression, with or without duraplasty, is preferable helpful procedures in symptomatic patients although its mechanism is still unclear.Tethered Cord Syndrome (TCS) is characterized by clinical signs and symptoms such as back/leg pain, orthopedic abnormalities (including scoliosis and foot deformities) and AIm: The Chiari Malformation I (CM I) and the tethered cord syndrome (TCS) are both congenital abnormalities whose mechanisms are still not fully understood.The association of CM I and TCS has been reported only a few times previously.mATERIAl and mEThODS: This retrospective study included 7 patients who were diagnosed with CM I and TCS, managed by cutting of the filum terminale. RESulTS:The mean follow-up period was 21 months and 28 days.Although all patients underwent an untethering surgical procedure by cutting the filum terminale only, all patients reported significant early postsurgical resolution of CM I symptoms and symptoms related to TCS as well.CONCluSION: Patients with symptomatic CM I, even if lumbar MRI is normal and the patient asymptomatic for TCS, may have tethered spinal cord at the same time.It seems it would be worthwhile to investigate CM I patients for occult TCS with spinal somatosensory evoked potentials.