Dandy Walker malformation variant late presentation with childhood blindness.html

Niger J Paed 2015; 42 (1): 73 –75

CASE REPORT

Ndu Ik

Dandy Walker malformation

Chinawa JM

Chikani M

(variant): late presentation with

Ibekwe R

childhood blindness

Aronu AE

Edelu BO

Asinobi I

DOI:http://dx.doi.org/10.4314/njp.v42i1,17

Accepted: 1st October 2014

Abstract: We present a rare case

remarkable.

Unfortunately

of Dandy Walker Syndrome in a

never regained sight. The purpose

Ndu Ik

(

)

child who presents with com-

of presenting this case report is to

Department of Paediatrics,

plaints of frontal headache, neck

highlight the distinctive manifesta-

Enugu State University Teaching

tion of Dandy walker syndrome to

Hospital

pain, fever, progressive visual

impairment and multiple general-

enhance early diagnosis, prompt

Chinawa JM, Ibekwe R, Aronu AE

ized tonic clonic seizures, inabil-

intervention and better outcome

Edelu BO, Asinobi I

ity to stand and urinary inconti-

Department of Paediatrics,

nence. Given the clinical and

Key words: Dandy Walker syn-

neuro-imaging findings, the diag-

drome; congenital brain malforma-

Chikani M

nosis of Dandy Walker Variant

tion; childhood blindness; hydro-

Department of Surgery,

was made. Post surgical recovery

cephalus

University of Nigeria Teaching

(Ventriculo peritoneal shunt) was

Hospital, Ituku Ozalle Enugu, Nigeria.

Introduction

Walker malformation, Dandy Walker variant, and mega

cisterna magna. The classic triad in Dandy Walker mal-

Dandy Walker Syndrome is a rare congenital malforma-

formation consists of dysgenesis of the cerebellar ver-

tion of the central nervous system. It results from a

mis, cystic dilatation of the fourth ventricle, enlargement

developmental failure of the roof of the fourth ventricle

of the posterior fossa. Dandy-Walker variant is less se-

which occurs during embryogenesis. It has been

vere than Dandy Walker malformation and is character-

reported in identical twins as well as in one identical

ized by variable hypoplasia of the cerebellar vermis,

twin but not the other, suggesting a combination of ge-

cystic posterior mass, and no enlargement of the poste-

netic and environmental influences. Molecular genetic

rior fossa. An enlarged cisterna magna, normal vermis

and 4 ventricle are seen in mega cisterna magna.

studies have detected deletion of cerebellar genes Z1C1

and Z1C4 . Incidence is 1:25,000-30,000 in the Western

hemisphere and 1:100,000 in Saudi Arabia. It is com-

Pathogenesis involves failure of regression of the em-

moner in females though male preponderance has been

bryonic anterior membranous area of the rhomben-

reported in India

3,4

. Local incidence rates are not

cephalic roof which leads to cystic dilatation and ver-

mian dysgenesis . The fourth ventricle is grossly mis-

known.

shapen because it is a membrane-wrapped cyst that ex-

The association of vermian hypoplasia, posterior fossa

tends into the foramen magnum as far as C2. The cyst

cyst and hydrocephalus was first reported by Sutton in

can also herniate upwards through the tentorial hiatus

1887 but Dandy and Black fan were the first to describe

elevating the torcula herophili and lateral sinuses, caus-

the condition as a clinical triad in 1914. The primary

ing a functional aqueductal stenosis with resultant hy-

drocephalus .

defect was thought to be atresia of the foramina of

Luschka and Magendie. This was however refuted by

Benda, in 1954, who concluded that the primary anom-

The clinical features depend on the effects produced by

aly was maldevelopment of the vermis and not necessar-

the cyst, the presence or absence of hydrocephalus and

ily due to foraminal atresia, because some autopsy cases

associated anomalies. Infants may present with progres-

had patent foramina and introduced the eponym ‘Dandy

sive skull enlargement and slow motor development.

Walker Syndrome’ .

Older children with hydrocephalus may present with

signs of raised intracranial pressure . Patients could be

The term Dandy Walker Syndrome or complex doesn’t

asymptomatic as seen in people with Dandy Walker

represent a single entity but refers to a spectrum/

variant who live their entire lives without any

continuum of posterior fossa cystic malformations.

symptoms.

Currently Three types have been described: Dandy-

Dandy-Walker syndrome often occurs in patients

Fig 1: CT Scan report

with PHACE syndrome and an emerging class of dis-

of the patient

eases called ciliopathies. Diagnosis is by CT scan which

can distinguish between hydrocephalus associated with

Dandy-Walker and hydrocephalus associated with other

etiologies. MRI is performed for detailed evaluation of

Dandy-Walker malformation lesions and complications

after the diagnosis is suspected using computed tomo-

graphy (CT) and ultra-sound . USS is used for prenatal

diagnosis and it is particularly used for postnatal follow-

up studies of hydrocephalus . Treatment involves sur-

gery, management of associated problems and genetic

Discussion

counseling. This case is being reported because of its

rarity and the need for a high index of suspicion in clini-

Dandy Walker Syndrome is a rare congenital malforma-

tion of the Central Nervous System . It could arise as a

cal practice. Early identification and appropriate inter-

vention can significantly improve quality of life.

genetically sporadic disorder and this may be the cause

of the index case. However molecular genetic studies to

Case report

detect deletion of cerebellar genes Z1C1 and Z1C4 were

not done because of laboratory limitations. It is reported

Eleven year old male who was referred from Federal

to be commoner in females, though the present case is

medical centre Asaba with complaints of continuous

male. Other predisposing factors include first trimester

fever, frontal headache, early morning effortless vomit-

exposure to rubella, cytomegalovirus, toxoplasmosis,

warfarin, alcohol, and isotretinoin . We could however

ting and neck pain that progressed to retraction of 8

weeks duration. There were also multiple seizures, tonic

not ascertain if our patient was exposed to these vari-

clonic with loss of consicusness, progressive visual im-

ables above in utero.

pairment as revealed by findoscopy, that progressed to

blindness with aggressiveness, out of school with nor-

Some patients may be asymptomatic with normal intrac-

mal development milestone. He eventually couldn’t

ranial pressure or they may have only mild unsteadiness

stand and also developed urinary incontinence over the

of gait or intellectual impairment until the syndrome is

last 2/52. General examination revealed a fully con-

activated by head trauma or a systemic infection. Our

scious but very irritable child, anthropometry (especially

patient developed the symptoms at the age of 11 years

occipito- frontal circumference) was within normal lim-

after a febrile illness. Post meningitic occlusion of the

foramina of Luschka and Magendie has been reported

its. CNS exam revealed Positive meningeal signs, Pupils

5mm dilated reacting sluggishly to light, Fundoscopy

and this may have complicated the underlying congeni-

revealed bilateral papilloedema, optic atrophy. There

tal abnormality which led to the development of the

was global hypertonia and hyperreflexia and truncal

clinical features at presentation in the index patient.

ataxia earlier and Blood pressure was elevated (150/130

The classical triad of hydrocephalus in an older child

mmHg) lately. Initial Diagnosis of Post Meningitic Hy-

whose sutures are supposed to have fused includes de-

drocephalus was made to rule out an SOL. Routine in-

mentia, urinary incontinence, inablity to walk or ataxia.

vestigations: FBC, SEUCR, Urinalysis, RVS (negative)

We noted two out of the triad in our case. These are due

were essentially normal, CT Scan report: Dandy Walker

to pressure effects of long standing hydrocephalus and

Variant. See fig 1. Visual acuity showed no perception

the minimum requirements for the shunt replacement or

to light. Given the history and unique clinico-

endoscopic third ventriculostomy operations are, the

radiological features, the diagnosis of Dandy Walker

presence of at least two compo-nents of the clinical

(variant) was made. Given the history and unique clinico

triad, presence of ventriculomegaly, and normal opening

-radiological features, the diagnosis of Dandy Walker

pressure of CSF . The raised blood pressure was a com-

(variant) was made. Treatment was with phenobarb,

pensatory mechanism to maintain cerebral perfusion and

Antibiotics Rocephin because meningitis was suspected.

the eventual progression to neck retraction was possibly

Decongestants was given to reduce the raised intracra-

an ominous sign of coning. Visual impairment initially

nial pressure since fundoscopy revealed bilateral papil-

was not taken serious by mother till he became com-

lopoedema, though hydrallazine was used to to reduce

pletely blind and required assistance to move around.

the blood pressure but it still remained high. Ventriculo

The optic nerve is very fragile and is easily damaged by

peritoneal shunt was done on the 9 day, Post surgical

raised intracranial pressure. The optic artery is in the

condition was satisfactory. Seizures stopped, blood pres-

centre of the optic sheath and resultant optic ischemia

sure

normalized and patient subsequently became am-

and optic atrophy lead to irreversible blindness and this

bulant and followed up in the clinic, however visual

occurred in the index case. Early surgical intervention

acuity still showed no perception to light. Unfortunately

may have arrested this.

he never regained sight.

Diagnosis is by CT scan which can distinguish between

Visual impairment initially was not taken serious by

hydrocephalus associated with Dandy-Walker and hy-

drocephalus associated with other etiologies . The CT

mother till he became completely blind and required

assistance to move around

scan for the index case revealed tri-ventricular dilatation

and communication between the fourth ventricle and

cyst at the level of petrous bone with mastoid air cells.

In a resource poor country like ours, high index of

suspicion, early diagnosis and timely referral are key

notes

Conclusion

Conflict of interest: None

Funding: None

Dandy walker syndrome is a rare anomaly. Early surgi-

cal intervention may offer a good and long term results.

References

Alexiou GA, Prodromou N. Dandy

Barrack S. Dandy-Walker syn-

13. Metry DW, Dowd CF, Barkovich

Walker Malformations. In: Manto

drome [Internet]. 2011 . Available

AJ, Frieden IJ. The many faces of

M, Schmahmann JD, Rossi F,

from: https://

PHACE syndrome. J. Pedi-

Gruol DL, Koibuchi N, editors.

jneurology.wordpress.com/article/

atr. 2001;139:117–23.

Handbook of the cerebellum and

dandy-walker-syndrome.Assesed

14. Badano Jose L, Norimasa M,

cerebellar disorders. 1 ed. Nether-

on 21st march,2014

Beales PL, Katsanis N. The

lands. Springer Netherlands; 2013.

Benda CE. The Dandy-Walker

Ciliopathies: An Emerging Class

Haslam RHA. Congenital anoma-

syndrome or the so-called atresia

of Human Genetic Disorders. An-

lies of the central nervous system.

of the foramen of Magendie. J

nual Review of Genomics and

In: Nelson WE, Behrman RE,

Neuropathol Exp Neurol

Human Genetics. 2006;7:125–48.

Kliegman RM, Arvin AM, editors.

1954;13:14-29.

15. Hamid HA. Review article: Dandy

Nelson textbook of paediatrics.

Alam A, Chander BN, Bhatia M.

Walker Malformation. Egypt. J.

15 ed. Philadelphia. WB Saun-

Dandy walker variant: Prenatal

Hum Genet. 2007;8:115-20

ders Company; 1996.

diagnosis by ultrasonography. Med

16. Dandy Walker syndrome.

Albright AL, Pollack IF. Princi-

J Armed Forces India.2004;60:287

[Internet] [cited 2014 Apr 4]

ples and Practice of Pediatric Neu-

–9

Available from: http://

rosurgery. 2 ed New York:

10. Incesu L, Khosla A. Imaging in

www.medgyan.com/index.php?

Thieme; 2011.

Dandy-Walker syndrome

option=symptoms&deId=1090

Ohaegbulam SC, Afifi H. Dandy-

[Internet]. 2013 [cited 2014 Mar

17. Manhant S, Manhant P, Biswas R.

Walker Syndrome: incidence in a

21]. Available from: http://

BMJ Case Reports2012;doi:10.

defined population of Tabuk,

emedicine.medscape.com/

1136/bcr.01.2012.5686

Saudi Arabia. Neuroepidemiology

article/408059-overview

18. Taskin MM. Normal pressure hy-

2001;20:150-2.

11. Thamburaj VA. Atlas of Instru-

drocephalus is a treatable syn-

Ozgen T, Acikgoz B. CSF dynam-

ments in Otolaryngology Head and

drome. Dü ş ünen Adam. 2008;

Neck Surgery. 1 ed New Delhi:

ics in Dandy-Walker syndrome.

2145-58

Acta Neurochirurgica 1990;104:

JP Medical Ltd; 2012

54-8

12. Dandy walker variant. http://

W.E. Dandy, K.D. Blackfan. Inter-

www.rightdiagnosis.com/d/

nal hydrocephalus: an experimen-

dandy_walker_variant/intro.htm

tal, clinical, and pathological

study, Am. J. Dis. Child. 1914;

8:406–82.