Table 1. Clinical findings in 415 patients with Chiari malformation type I.

	CMI
Number of patients	415
Sex (M/F)	122/293
Age (y)	42.2±50.9
Age at diagnosis	30.6±58.7/323
Hydrocephalus	57/377 (15.1%)
Syringomyelia	133/379 (35.1%)
Intracranial Hypertension	20/376 (5.3%)
Retrocurved Odontoid	40/352 (11.4%)
Basilar impression	11/382 (2.3%)
Platibasia	8/382 (2.1%)
Klippel-Feil Malformation	3/377 (0.8%)
Other Craniocervical Malformations	24/377 (6.4%)
SIGNS AND SYMPTOMS
Time elapsed from onset (mo)	113.3±59.4/323
Headache	246/356 (69.1%)
Occipital Headache/Cervicalgia	97/224 (43.3%)
Cough Headache	87/358 (24.3%)
Dizziness	128/365 (35.1%)
Vertigo	82/365 (22.5%)
Visual Alterations	71/364 (19.5%)
Nystagmus	41/276 (14.8%)
Kyphoscoliosis	30/160 (18.7%)
Fatigue	102/363 (28.1%)
Instability	117/364 (32.1%)
Sensory Loss	108/364 (29.7%)
Motor Weakness	123/366 (33.6%)
Dysphagia	67/365 (18.3%)
Dysphonia	16/365 (4.4%)
Gait Disturbances	73/364 (20.0%)
Paresthesia Upper Limbs	112/365 (30.7%)
Paresthesia Lower Limbs	47/366 (12.9%)
Upper Limb Pain	47/365 (12.9%)
Lower Limb Pain	16/365 (4.4%)
Neck Pain	169/366 (46.2%)
Difficulty Swallowing	66/365 (18.1%)
Anxiety	38/360 (10.5%)
Depression	33/361 (9.1%)
Neurofibromatosis type 1	45/382 (11.8%)
TREATMENT
Posterior fossa reconstruction	210/376 (55.8%)