ORIGINAL

Niger J Paed 2014; 41 (2):133 –135

Eyong KI

Philip-Ephraim EE

Inah G

Cranial nerve palsies in Nigerian

children

Ikobah JM

Ekanem EE

Asindi AA

DOI:http://dx.doi.org/10.4314/njp.v41i2,11

Accepted: 8th January 2014

Abstract: Background: Cranial

Results: Of the 285 with neuro-

logical problems 23 (8.1%) had

cranial nerve palsies. Fifteen

(65.2%) of the children had single

cranial nerve palsies while eight

(34.8%) had multiple cranial

nerves involvement. Of the 43

nerves involved, the facial nerve

was the commonest (38.3%) fol-

lowed by the oculomotor (23.5%)

and abducens (20.6%). Intracranial

infections such as meningitis, viral

encephalitis and brain abscess

were incriminated in 60.8% of the

patients and 70.6% of the nerves

involved.

Conclusion: Cranial nerve palsies

cause handicap and cosmetic prob-

lems. It is recommended that every

child with cranial neuropathy

should be evaluated for intracra-

nial infections among other differ-

entials. Prompt diagnosis, treat-

ment and immunisation against

related infections is paramount.

nerve palsies are common clinical

problem routinely encountered in

neurological practice; the dysfunc-

tion can occur at any point in the

course of the nerve and may point

to serious pathology. The aim of

this study was to determine the

pattern and underlying aetiology of

cranial nerve palsies in Nigerian

children.

Method: Children in the Children’s

Emergency Unit and the Children’s

Ward of the University of Calabar

Teaching Hospital, Calabar, Nige-

ria, with neurological problems

over a 12-month period (January

through December 2012), were

recruited into the study. Each child

was admitted and evaluated by the

Paediatric Neurology Unit. Those

with cranial nerve palsies were

selected for detailed analysis. The

biodata, clinical features and

Ekanem EE⁽

)

Eyong KI, Ikobah JM, Asindi AA

Department of Paediatrics,

Philip-Ephraim EE

Department of Internal Medicine,

Inah G

Department of Radiology,

University of Calabar, Teaching

Hospital Calabar,

Nigeria.

Email: profekanem@gmail.com

relevant laboratory results were

documented.

Introduction

underlying causes were largely trauma, intracranial

infections and tumours.

Cranial nerve palsy is a common clinical problem

1

routinely encountered in neurology practice. Dysfunc-

The pattern of cranial nerve palsy is likely to differ with

age and may have a geographical variation. This pro-

spective study was therefore undertaken to determine the

pattern and the underlying aetiology of cranial nerve

palsies in Nigerian children. The study was conducted in

the University of Calabar Teaching Hospital (UCTH),

Calabar, in South-eastern Nigeria. The rationale was to

provide the reader with an overview of the diseases

which have a predilection for afflicting cranial nerves.

We hope that the result will help improve clinical diag-

nostic acumen and management in the region.

tion of a cranial nerve can occur from intrinsic brainstem

dysfunction to its peripheral course. Cranial nerves

palsies may be the earliest indication of an on-going

intracranial and extrac₁ranial pathology and may assist in

the diagnosis of such.

2

Anatomical patterns of cranial nerves involvement can

facilitate the determination of the primary lesion. Vari-

ous infections, malignant neoplasms and autoimmune

vasculitis are common disorders leading to cranial nerve

1

palsies. A large number of diffuse neurological disor-

.

ders (e.g. Guillain-Barre’ syndrome, myopathies) may

present with multiple cranial nerve palsies.

Methodology

In a study on cranial palsies in American adults, Keane

3

JR found that the most commonly involved nerves were

This prospective survey was conducted within a 12-

month period, January through December 2012. Ethical

the sixth, second, fourth and seventh. In that series the

1

34

approval was obtained from the Research Ethics

Committee of the University of Calabar Teaching

Meningitis (2 of them, tuberculous)) was the commonest

underlying cause of the nerve palsy 15 (44.2% of

nerves) followed by suspected viral encephalitis 8

(23.5%). In 14(60.8%) of the 23 children, the palsy was

causally associated with infections (Table2). Infection

(meningitis, encephalitis and brain abscess) was also

associated with 76.5%of the nerve damage (26 of 34

nerves).

Hospital. As a Departmental policy, every child admit-

ted in the Children Emergency Room (CHER) and the

Children’s ward of the UCTH with significant neuro-

logical deficit was referred to the Paediatric Neurology

Unit for further evaluation or admission. Inpatients of

other paediatric subspecialties so referred had a thor-

ough and detailed review of their nervous system. All

the patients whose clinical features involved cranial

nerve(s) were noted. When indicated, and considered

safe, a spinal tap was undertaken and the CSF analysed.

For the purpose of this survey, the demographic data,

clinical features, diagnosis, and relevant laboratory re-

sults were filled in a proforma form. Due to financial

constraints, only one child with sickle cell stroke was

able to afford neuroimaging scan (CT and MRI each).

There were no facilities for nerve conduction test. The

diagnosis of viral encephalitis was made on clinical

grounds as the hospital has no facility for viral studies.

Viral encephalopathy was therefore diagnosed in chil-

dren with fever accompanied by acute neurological signs

such as irritability, convulsions with altered level of

consciousness whose cerebrospinal fluid was clear and

sterile on routine culture technique. All the children

were treated as appropriate, based on the diagnosis

made. On discharge, patients were followed up weekly

and then fortnightly at the paediatric Neurology Clinic.

Data obtained was analysed using tables and simple

proportions.

Table 2: No. of nerves involved related to presumed aetiology

in 23 children

Aetiology

Meningitis

Viral encephalitis

Cerebral abscess

Bell’s palsy

number

15

8

3

percentage

44.2

23.5

8.8

Sickle cell disease

Leukaemia

2

5.9

Cerebral contusion(RTA)

Total

1

34

2.9

100

RTA = road traffic accident

Cranial nerves VI and VII were largely associated with

meningitis. The two cases of sickle cell stroke had facial

nerve palsy. Two children had leukaemia received

vincristine as part of their chemotherapy regimen.

(

Table 3).

Table 3: Distribution of nerve palsy related to aetiology

Type of cranial nerve

Aetiology

Optic Oculomotor Abducens Facial Auditory Total

Meningitis

1

2

-

2

3

-

2

-

5

2

-

4

-

1

-

13

8

2

3

Viral encephalitis

TB meningitis

Bell’s palsy

Cerebral abscess

Sickle cell stroke

Leukaemia

1

3

1

2

Results

-

2

1

During the period of the survey, 2199 children were

admitted into the Ward and CHER. Of these, 285 (13%)

had neurologically related problems. Of the 285, 23

-

Contusion injury

(RTA)

Total

-

3

1

8

-

7

-

13

-

3

1

34

(

8.1%) had cranial nerve palsies. Thirteen of the chil-

dren were males while 10 were females; one child was

aged less than one year, 13 were 1-5 years and nine were

above five years. The oldest child in the series was 12

years old and the youngest, eight months.

Figure 1a and 1b are MRI of a 4-year old female with

sickle cell stroke with facial nerve palsy showing a right

parietal lobe infarct and atrophy.

A total of 34 nerves were affected in the 23 children; the

most susceptible nerve was the facial (38.3% of the 34

nerves) followed by oculomotor (23.5%) and abducens

nerve (20.6%) (Table 1). Others were the optic and co-

chlear (3 each). Fifteen (65.2%) of the children had

single cranial nerve palsies while 8 (34.8%) had multi-

ple cranial nerve involvement( 2 nerves in 6, 3 nerves in

Fig 1a

Fig 1b

2

). Three children had bilateral oculomotor palsy each.

The two cases with three-nerve involvement were re-

lated to viral encephalitis and cerebral contusion from

automobile accident respectively.

Table 1: Distribution of 34 cranial nerves* involved in 23

children

MRI of brain of sickle cell patients

Nerve

no.

percentage

Facial

13

8

7

3

38.3

23.5

20.6

8.8

Oculomotor

Abducens

Optic nerve

Auditory

8.8

1

35

Discussion

studies in adult populations which identified the

abducens n_,₇erve as the most vulnerable in various pa-

3

To our knowledge, no large series of cranial neuropa-

thies on Nigerian children is available. This study is

limited due to the small number of subjects and investi-

gative handicap but the findings appear to offer some

reasonable and helpful clues as to the pattern of cranial

palsy and the aetiopathologies in Nigerian children. We

regard this as a preliminary study which is to lay a foun-

dation for more elaborate, and hopefully, a multicentre

survey. Being preliminary, we do not intend to relate the

result to other available studies but just discuss the find-

ings as they are.

thologies. This may be related to the aetiology. Com-

paratively, meningitis and viral infections such as rhi-

novirus and Herpes Simplex are more common events in

children. The inflammatory swelling with compression

and subsequent paralysis of the VII nerve in its long

course within the facial canal may be an additional rea-

son w₈_,₉hy the facial nerve is most vulnerable in chil-

dren.

Vincristine, a component of chemotherapy in

childho₁₀od leukaemia, can cause neuropathy as a side

effect.

Interestingly, despite the high prevalence paediatric

HIV/AIDS in Nigerian children, the study did not cap-

The study has identified intracranial infections as the

most probable cause of cranial nerve palsy in Nigerian

children. In contrast, cranial palsies are frequently seen

as post-traumatic and ischaemic syndromes in adult

ture any case; we are unable to explain

this. It is

also interesting that intracranial tumour did not feature

in this survey. Solid intracranial tumours are known to

be rare in Nigerian paediatric population.

3

population. In this series intracranial infection alone

constituted 76.5% nerve damage. A majority of the chil-

dren (60.8%) derived their neuropathy from infection.

The aetiology of Bell’s palsy may not be completely

understood; however, a reactivation of herpes simplex

virus type 1 (HSV-_,₅1) infection has been postulated to

Conclusion

4

cause the disease. Also, multiple case reports have

In conclusion, Cranial nerve palsies may be a common

clinical problem encountered in neurological practice

and their presence is an indication of an underlying in-

tracranial pathology. The incapacitation and the cos-

metic disfigurement they create can be a cause of great

concern to the physician, patients and parents. That in-

tracranial infections constitute the commonest cause

places a premium on prompt diagnosis and therapeutic

intervention in children with these underlying disease

conditions. But more importantly is the relevance of

routine immunisation against common bacterial and

viral agents causing meningitides and encephalitis in the

environment. Sometimes, despite extensive biochemical

and radiological work-up, the accurate diagnosis may

not be established. Few such patients represent

"idiopathic" variety of cranial nerve₁involvement and

show good response to corticosteroids.

described Bell’s palsy following immunization with

6

influenza and hepatitis B virus (HBV) vaccines. Proba-

bly, these attenuated live-vaccines can convert to be-

come neurovirulent. Considering these postulations, the

three cases with Bell’s palsy may additionally be re-

garded as being infective in origin. This association be-

tween infections and cranial neuropathy underscores the

importance of prompt diagnosis and therapeutic inter-

vention in children with these conditions. But more

importantly is the relevance of routine immunisation

against common bacterial and viral agents causing

meningits and encephalitis in the environment.

The study has shown that the most susceptible cranial

nerve is the facial (38.3%), with the affection of the ocu-

lomotor (8%) and abducens (7%) to a less extent. In the

present study, a majority of the underlying disease

entities have involved nerve VII. This is in contrast to

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