Chiari Type I malformation and syringomyelia in unrelated patients with blepharophimosis. Report of two cases

Clinical diagnosis-part I: what is really caused by Chiari I

PURPOSE

Chiari malformation is a group of congenital malformations involving the brainstem, cerebellum, and upper spinal cord, frequently identified in both young adults and in children. Chiari I malformation (CM1), classically defined as a caudal displacement of the cerebellar tonsils through the foramen magnum into the spinal cord, is the most common clinical type. A syringomyelia can be associated at the time of the diagnosis or appear secondarily and manifest with medullary symptoms. The aim of this paper is to update the knowledge on clinical manifestations specifically related to Chiari I malformation with or without syringomyelia in the pediatric population.

METHODS

Current literature with focus on relevant clinical pediatric issues is reviewed and discussed, comparing with those related to adults; we include the results of a 10-year single-center experience on 600 CM1 patients.

RESULTS AND CONCLUSIONS

Herniation of the cerebellar tonsils may lead to significant clinical symptoms, including neck and cervical pain, short-lasting occipital "cough" headache, dizziness, and gait impairment; in children younger than 3 years, oropharyngeal symptoms are prevalent (sleep apnea, feeding problems) whereas in those older than 3 years, a higher incidence of cough headache and scoliosis is reported. CM1 clinical features, both in children and in adults, have in common the presence of anatomical deformities of the brainstem and cerebellum. Clinical myelopathy (sensory/autonomic disorders, motor weakness) can result from direct compression of the cervical spinal cord by the herniated cerebellar tonsils or can be due to the presence of a syrinx, reported in association with Chiari I between 35 and 75% of pediatric patients. Similarly, in our series (440 females, 160 males, 98% > 18 years), syringomyelia associated with Chiari I was ranging from 40 to 60% (respectively in asymptomatic and symptomatic groups); headache was reported in 65%. Sensory disturbances (48%), cranial nerve deficits (45%), motor weakness (32%), and autonomic disorders (35%) were the most frequent neurological signs in our cohort. In Chiari I malformation, cervical pain and occipital cough headache are the most characteristic presenting symptoms, both in old children and in adults; however, headache is often multifactorial, and CM1 patients can report a wide variety of non-specific symptoms and signs. Clinical diagnostic CM1 criteria, shared at the national and international level, are recommended with the aim to avoid consequent controversies on diagnosis and on surgical decision making.

New presenting symptoms of Chiari I malformation: report of two cases

OBJECTIVE

Chiari Malformation type I nowadays represents one of the most debated and treated entities of neurosurgery. Several different symptoms of cerebellar, brainstem and spinal cord pathology have been described and attributed to this malformation. In this paper, we reported a very uncommon association of Chiari I malformation with isolated hemihypertrophy in one case and clawing hands in the second case.

CASE REPORTS

We report the first case of a 14-year-old girl who presented with a 6-month history of left claw hand, with no evidence of radiculopathy and myopathy; MRI scan revealed a symmetrical herniation of cerebellar tonsils to the level of C1 (0.7 mm), downward displacement of the obex and holocord syrinx. We assisted to the complete resolution of the left clawing hand immediately after decompressive craniectomy, C1 laminectomy, opening of the dura and collagen matrix duraplasty. The second case is a 9-year-old boy who presented with hemihypertrophy affecting the left arm and chest wall, without involvement of the face.

CONCLUSIONS

These case reports can suggest the association of hemihypertrophy and claw hand with Chiari I malformation and syringomyelia. Further studies are necessary to assess the real incidence of focal motor deficits and mesodermic disorders in Chiari I malformation in order to clarify their pathogenetical mechanisms.

Volumetric analysis of the posterior cranial fossa in a family with four generations of the Chiari malformation Type I

OBJECT

Many authors have concluded that the Chiari malformation Type I (CM-I) is due to a smaller than normal posterior cranial fossa. In order to establish this smaller geometry as the cause of hindbrain herniation in a family, the authors of this paper performed volumetric analysis in a family found to have this malformation documented in 4 generations.

METHODS

Members from this family found to have a CM-I by imaging underwent volumetric analysis of their posterior cranial fossa using the Cavalieri method.

RESULTS

No member of this family found to have CM-I on preoperative imaging had a posterior fossa that was significantly smaller than that of age-matched controls.

CONCLUSIONS

The results of this study demonstrate that not all patients with a CM-I will have a reduced posterior cranial fossa volume. Although the mechanism for the development of hindbrain herniation in this cohort is unknown, this manifestation can be seen in multiple generations of a familial aggregation with normal posterior fossa capacity.

Chiari type I malformation in four unrelated patients affected with Fabry disease

Fabry disease (FD) is an X-linked inborn error of metabolism resulting from the deficient activity of alpha-galactosidase A which leads to the widespread deposition of glycosphingolipids in lysosomes, and to ischemic complications involving kidneys, heart and brain. Among neurological symptoms, strokes and transient ischemic attacks (TIA) have been reported. A 30-year-old male patient, with FD, was referred to us for evaluation of a sudden episode of dizziness, with disequilibrium, and diplopia, in agreement with the diagnosis of a TIA. Head magnetic resonance imaging (MRI) showed no cerebrovascular involvement but revealed the presence of Chiari type I malformation (CMI). We subsequently performed head MRI in a cohort of 44 consecutive hemizygous male patients and seven heterozygous females affected with FD, and identified three additional cases (two males and one female) of CMI. Whether the association is coincidental or not will need further studies but our data suggest that CMI should be ruled out in all Fabry patients.

Familial Chiari type I malformation with syringomyelia in two siblings: case report and review of the literature

OBJECTIVE

Familial cases of Chiari malformation with syringomyelia are rare. The majority of the reported series and case reports detail sporadic cases. The authors report two siblings who presented with Chiari type I malformation and syringomyelia (CMI+S).

CLINICAL PRESENTATION

We report two sisters who each presented with scoliosis on routine school physicals. Their clinical examination was unremarkable; however, imaging studies demonstrated a Chiari malformation with syringomyelia. Both underwent cervicomedullary decompression, and follow-up imaging studies revealed resolution of the syringomyelia.

CONCLUSION

A review of the literature reveals fewer than ten previous reports of familial CMI+S in the past 30 years. Although rare, the existence of familial cases of CMI+S suggests a genetic component to the pathogenesis of this condition in at least a proportion of patients. Neurosurgeons should be aware of the familial aggregation of CMI+S.

Evaluation and management of the Chiari malformation type 1 for the primary care pediatrician

Diagnosis and treatment of CMI is undergoing reexamination that includes redefinition of the anatomic Chiari malformation and refinement and redefinition of the clinical syndrome. Children with SMI present with head pain of some kind, a neurologic deficit, or with signs of spinal cord dysfunction from syrinx. Some will present with no clinical syndrome at all. Presence of anatomic Chiari malformation or compelling clinical Chiari syndrome should lead to evaluation by a neurologist or neurosurgeon experienced with the syndromes and their treatment. Treatment options are varied but usually result in resolution of symptoms. When symptoms persist after surgery, management is complex and not uniformly successful, even in the most experienced hands.