http://indianpediatrics.net/oct2006/oct-920-922.htm

Chiari Malformation Type II with Vanishing Cerebellum

An eight-month-old baby, the second of two siblings born to non-consanguinous parents, presented with delayed milestones and a history of a lumbosacral swelling which was operated in the early neonatal period.

MR imaging revealed a small posterior fossa occupied by the occipital lobes and a profoundly small cerebellum (Fig 1). The tentorial incisura was heart-shaped. Sagittal sections demonstrated hypoplastic cord-like cerebellar tonsils herniating through the foramen magnum into the upper cervical canal and an elongated poorly-formed fourth ventricle (Fig. 2). Other findings were a small-sized pons with loss of normal pontine prominence, caudal elongation of the medulla and beaked tectal plate. The torcular hetero-phili was low-placed and supratentorial hydrocephalus was present. The massa inter-media was absent and the falx was hypoplastic with consequent interdigitations of gyri.

 

Fig. 1. MRI Axial SE Small posterior fossa occupied by the occipital lobes (white arrow) and a profoundly small cerebellum (black arrow).

 Fig. 2. SAG T1 WI: Hypoplastic cord-like cerebellar tonsil herniating through the foramen magnum into the upper cervical canal (Black arrow), elongated poorly formed tube-like fourth ventricle (white arrow), small sized pons with loss of the normal pontine prominence, beaked tectal plate, absent massa intermedia

MR images of the lumbosacral spine revealed dysraphism and lumbar meningomyelocele with tethering of the cord.

In 1891, Hans Chiari first described an anomaly encompassing elongated peg-like cerebellar tonsils displaced into the upper cervical canal through the foramen magnum to be later known as the Chiari type I malformation. Chiari type II anomaly includes herniation of the medulla, fourth ventricle and cerebellar vermis through the foramen magnum. Chiari III combines features of Chiari II with a high occipital or low cervical encephalocele. A fourth variety includes severe hypoplasia/aplasia in a diminutive posterior fossa.

The Chiari II malformation is always associated with a meningomyelocele. This condition includes downward displacement of medulla, fourth ventricle and cerebellum into the cervical spinal canal, with concomitant elongated pons and fourth ventricle, probably due to a relatively small posterior fossa.

These intracranial abnormalities are a result of incomplete closure of the neural tube, which prevents transient closure of the central canal that is essential for distension of the primitive ventricular system. The subsequent lack of the inductive effect of pressure and volume on the surrounding mesenchyme results in an abnormally shallow posterior fossa(1). Exceptionally, this transforaminal herniation results in ‘degeneration’ of cerebellar tissue, presenting as ‘the vanishing cerebellum in Chiari II malformation(2). The absence of a normal-sized posterior fossa precludes the diagnosis of cerebellar agenesis(3).

N. Chidambaranathan,Sumithra Reddy, 

Department of Radiology andImaging Sciences,

Apollo Hospitals,No. 21, Greams Lane, Chennai 600 006, India.

E-mail: drchidam@vsnl.net 

References

1. Bolthauser E, Schneider J, Kollias S, Waibel P, Weisser M. Vanishing cerebellum in myelomeningocele. Eur J Pediatr Neurol 2002; 6: 109-113.

2. Mclone DG, Knepper DA. The cause of Chiari II malformation. A unified theory. Pediatric Neuroscience 1989; 15: 1-12

3. Sener RN. Cerebellar agenesis versus vanishing cerebellum in Chiari II malformation. Comput Med Imaging Graphics 1995; 6: 491-494.

http://cupangkolam.wordpress.com/2010/05/27/sedikit-berbagi-tentang-penyakit-malformasi-chiari-dan-syringomyelia/

MALFORMASI CHIARIAtau sering disebut Arnold_Chiari Malformation, adalah tampilan genetic yang jarang terjadi dimana ada bagian otak yang tumbuh tidak normal.Malformasi mungkin terjadi pada bagian paling bawah otak atau bagian brain stem. Pertama ditemukan oleh seorang ahli pathologi Jerman bernama Arnold Chiari pada tahun 1891. Pada malformasi   otak terdesak karena posterior fossa kecil sehingga mengakibatkan munculnya tonsil. Malformasi sering terjadi karena bawaan sejak lahir dimana problem ini mumncul saat dewasa. Oleh karena itu malformasi sering diketahui saat sudah dewasa. Beberapa akibat malformasi dapat menyebabkan hydrocephalus, terbukanya spina bifida, atau bahkan syringomyela. Para peneliti belum mengetahui penyebab penyakit ini secara pasti. Satu hipotesa menyebutkan bahwa bagian bawah otak (the skull) terlalu kecil, sehingga cerebellum menurun. Teori lain menyebutkan overgrowth pada cerebral region. Pasien sering mengeluhkan pusing, ketika bersin pusing, rasa seperti terbakar, ketidakseimbangan, nyeri di leher atau sakit pada bagian tangan, memiliki problem visual atau spot-spot hitam pada penglihatan. Penyakit ini dapat dideteksi dengan MRI atau Contras MRI.

Gambar diambil dari link berikutSYRINGOMYELIASyringomyelia adalah penyakit degeneratif kronis progressif atau gangguan perkembangan sumsum tulang belakang yang ditandai dengan kelemahan tanpa rasa nyeri serta atrofi otot-otot lengan dan tangan yang disertai kedutan, refleks-refleks tendon menghilangdan terjadi mati rasa segmental tipe dissosiatif. Rasa nyeri seperti terbakar dan ngilu pada salah satu sisi tubuh, atau juga dirasakan pada wajah. Jika batuk atau bersin atau membungkuk akan merasakan ngilu di dasar kepala. Penyakit ini biasa muncul pada rentang usia 20-40 tahun, lelaki dan wanita punya resiko yang sama terkena penyakit ini.Pada syringomyela sering terbentuk syrinx, yakni rongga berisi cairan yang terbentuk pada tulang belakang, pada tungkai otak atau pada keduanya. Penyebab syrinx yang jarang terjadi ini umumnya terjadi karena bawaan sejak lahir dan kemudian untuk alasan yang kurang dipahami hal ini melebar selama usia remaja atau dewasa muda. Penderita sering mengalami kelainan struktur otak, tulang belakang, atau simpangan antara tengkorak dan tulang belakang. Syrinx sering menyebabkan luka atau tumor, dan sekitar 30% tumor tulang belakang terjadi karena syrinx. Syrinx berkembang pada tali tulang belakang dan menekan dari dalam, cenderung mempengaruhi serat yang melancarkan tanda dari otak pada gerak-gerik otot. Syrinx dapat terjadi di sepanjang tulang belakang, tetapi sering dimulai dari leher dan mungkin memanjang menurun sehingga mempengaruhi persyarafan seluruh tubuh.

Gambar diambil darihttp://en.wikipedia.org/wiki/Syringomyelia”>syringomyelaTESTIMONISuami saya adalah penderita Malformasi chiari dengan syringomyela. Tak ada penyebab secara pasti, awalnya tangan sering getar sendiri, utamanya ketika kelelahan. Punggung nyeri, sering merasakan kejut seperti kesetrum saat batuk atau bersin. Tanda-tanda seperti ini sudah kami periksakan dan beberapa dokter menyebutkan gejala stroke atau stroke ringan. 4 tahun yang lalu jari-jari tangan melemah, dan kelemahan ini kian hari kian bertambah hingga kedua lengan seperti tidak punya tenaga sama sekali. Perjalanan pengobatan kami yang telah kesana kemari serasa tak ada perkembangan pasti. Bahkan EMG yang dilakukan 2 tahun lalu masih menunjukkan hasil normal walaupun tangan kiri sudah melemah. 2 bulan lalu sebenarnya kami sudah merasa seperti lelah dan putus asa. Tetapi akhirnya ALLAH menjawab do’a kami dengan menunjukkan penyakit yang sebenarnya suami derita yang memang tergolong penyakit yang jarang terjadi.Hal ini berawal dari pemeriksaan MRI contras yang kami lakukan menunjukkan hasil bahwa ada penurunan posisi otak sekitar 3mm sehingga menimbulkan tonsil pada pangkal otak C1 dan syringomyelipada sumsum tulang belakang di ruas C4-C5. Sekalipun pernyataan dokter seperti ini membuat hati kami tak karuan karena mendengar jenis penyakit yang memang jarang terjadi atau langka juga berbagai resiko serta program dokter sebagai upaya penanganan penyakit ini yang tergolong cukup berat,tetapi kami masih bersyukur karena sepak terjang kami selama 4 tahun demi ingin mengetahui jenis penyakit dan upaya penyelesaiannya telah ditunjukkan ALLAH di depan kami. Sekalipun sangat berat terselip keyakinan kami bahwa sesulit apapun ALLAH akan meyertakan kemudahan dari jalan yang tak kami perkirakan.Dengan mempertebal keyakinan dan do’a juga semangat yang kami hembuskan pada batin kami, akhirnya kami memutuskan mengikuti program dokter dengan penanganan operasi yang diprogram 2 kali, pertama pada pangkal otak untuk penanganan malformasi chiari dan operasi kedua pada sumsum tulang belakang dengan pemasangan selang kecil pada ruas C5 sebagai penanganan syringomyelia. 40 hari bukan saat yang ringan melalui hari-hari di RS Karyadi Semarang. Berbagai tahapan medis harus dilalui dengan semangat sekalipun nyali kami harus naik turun karena kondisi kesehatan yang juga naik turun.

Alhamdulillah….tahap itu telah selesai kami lalui dengan berbagai kisah pahit manis bersama teman-teman kami berbagai penderita penyakit berat di bangsal Bedah Syaraf RS Karyadi Semarang. Tulisan ini sengaja kami buat untuk berbagi kisah dan penanganan kepada sesama penderita malformasi chiari dan syringomyela mengingat penyakit ini yang masih tergolong langka. Saat tulisan ini dibuat suami masih menjalani program Rehabilitasi Medis dengan 3 program, fisioterapi, orthose prothese dan terapi okuptasi.

http://www.mountsinai.org/patient-care/service-areas/neurology/diseases-and-conditions/chiari-malformation

Chiari malformation

DefinitionChiari malformation is an abnormality or structural defect in the cerebellum, the lower part of the brain in the back of the head that controls balance. The indented space at the base of the skull, above the foramen magnum, is a funnel-like opening to the spinal canal that normally holds the cerebellum and parts of the brainstem. A Chiari malformation occurs if part of the cerebellum extends below the foramen magnum.

Causes

There is no known cause for primary Chiari malformations. However, acquired or secondary Chiari malformations may arise from excessive drainage of spinal fluid from the lumbar or thoracic areas of the spine due to injury, exposure to harmful substances, or infection.

Primary or congenital Chiari malformation: structural defects in the brain and spinal cord that occur during fetal development

The bony space is typically deformed or smaller than normal, and the normal structures are crowded and compressed

Graphic image courtey of www.conquerchiari.org

Risks

Risk factors are traits or lifestyle habits associated with an increased chance of developing a disease or condition. There are no known risk factors for Chiari malformation.Chiari malformation can become a progressive disorder and lead to serious complications:

Hydrocephalus: accumulation of excess fluid within the brain Syringomyelia: a cavity or cyst (syrinx) forms within the spinal column Paralysis, which may occur due to the crowding and pressure on the spinal cord, tends to be

permanent, even after treatment with surgery Death: an uncommon outcome, usually early in infancy, when a child is born with severe

congenital abnormalities in other parts of the central nervous system

Symptoms

Chiari malformations are classified by type, depending on their severity, and symptoms vary according to the type.Symptoms that may occur with any of the three types:

Headaches, often severe, typically precipitated with sudden coughing, sneezing, or straining Neck pain Muscle weakness Numbness in arms, legs, or face Problems with balance and coordination Double or blurred vision Dizziness Swallowing difficulties Hydrocephalus Syringomyelia or syrinx (a cyst within the spinal cord); this may cause weakness, numbness,

tingling and/or clumsiness involving the upper and lower extremities Spinal curvature

Type I

Sometimes asymptomatic-often found by accident during an examination for another condition

Patients are usually in their mid- to late-thirties at diagnosis The syndrome is somewhat more common in women

Type II

A greater amount of tissue protrudes into the spinal canal compared with Type I Myelomeningocele: the spinal canal and backbone do not close before birth, causing the

spinal cord to protrude through an opening in the back. This can cause partial or complete paralysis below the spinal opening.

Type III

Severe neurological defects A portion of the lower back part of the brain (cerebellum) or the brainstem extends through an

abnormal opening in the back of the skull

Diagnosis

Diagnosis usually involves a thorough neurological exam and radiological imaging.

Complete physical examination in which the physician takes a medical history and asks whether symptoms such as head and neck pain are present; physician will also conduct a check of fine motor skills, reflexes, memory, cognition, balance, and cranial nerve function

Magnetic resonance imaging (MRI) is the imaging procedure most often used to diagnose a Chiari malformation

Computed tomography (CT scan) can identify hydrocephalus and bone abnormalities associated with Chiari malformation

X-ray of head and neck: can detect bone abnormalities often associated with Chiari malformation but cannot detect the Chiari malformation itself

Treatment

Treatment depends on the severity and characteristics of your condition.

Monitoring with regular examinations for those with no symptoms Headache and pain management with pain medication, physical therapy or a reduction in

activities can help manage symptoms Primary surgical repair to reduce pressure on the cerebellum and the spinal cord and restore

the normal flow of spinal fluid

The most common operation for Chiari malformation is posterior fossa craniectomy or posterior fossa decompression during which the surgeon removes a small section of bone in the back of the skull and possibly the upper cervical spine, relieving pressure by giving the brain and brainstem more room.Medications may ease certain symptoms, such as pain, but surgery is the only treatment available to correct functional disturbances or halt the progression of damage to the central nervous system. Primary repair of the Chiari malformation is frequently all that is required. Occasionally the hydrocephalus or spinal syrinx do not go away and require separate shunting procedures.Case StudyOne such patient was a man in his mid-thirties with a history of severe, progressive headaches that were made worse by coughing, bending, and stooping. He had noticed a change in the quality of his voice and a difficulty swallowing. He also found himself gasping for breath on occasion. His workup led to an MRI scan (left), which demonstrated a severe Chiari malformation associated with compression of the cervicomedullary junction and a large cervical syrinx. After decompressive surgery

and recovery, the patient returned home and noticed almost immediate improvement in his symptoms. He continued to improve and returned to his normal work schedule.

Preoperative MRI showing hydrocephalus, herniation of cerebellar tonsils and spinal syrinx

Postoperative MRI showing decrease in hydrocephalus, return to normal position of cerebellar tonsils, and resolution of syrinxMRI images used with permission from Joshua B. Bederson, MD

Prevention

There is no known way to prevent Chiari malformations. To learn more about Chiari malformations call the Mount Sinai Department of Neurosurgery at 212-241-2377.Written by the Mount Sinai Department of Neurosurgery.This information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. Call you health care provider immediately if you think you may have a medical emergency. Always seek the advice of your physician or other qualified health provider before starting any new treatment or with any questions you may have regarding a medical condition.