tell us how the sample directly compares to internationalpopulations. They can, however, reassure us that the AIMShasn’t changed and results from the AIMS should be uti-lized as they have been in the past. The authors stressappropriate caution in interpreting the AIMS related to

developmental windows, cut-off points, and other history.Serendipitously, their methodology is well described andcould be readily replicated with alternate populations, workthat might contribute additional information on the bigquestions of motor development.

REFERENCES

1. Piper M, Darrah J. Motor Assessment of the Developing

Infant. Philadelphia, PA: Saunders, 1994.

2. Pin T, Eldridge B, Galea MP. A review of the effects of

sleep position, play position, and equipment use on

motor development in infants. Dev Med Child Neurol

2007; 49: 858–67.

3. Darrah J, Bartlett D, Maguire TO, Avison WR, Lacaze-

Masmonteil T. Have infant gross motor abilities chan-

ged in 20 years? A re-evaluation of the Alberta Infant

Motor Scale normative values Dev Med Child Neurol

2014; 56: 877–81.

Are proprioceptive functions affected in Duchenne musculardystrophy?

DIDO GREENCentre for Rehabilitation, Oxford Brookes University, Oxford, UK.

doi: 10.1111/dmcn.12476

This commentary is on the original article by Troise et al. on pages882–887 of this issue.

The processing of sensory and perceptual informationhas long been a focus of interest for researchers and cli-nicians in attempting to understand the motor coordina-tion difficulties of children with developmental disorders1

and those with cerebral palsy (CP).2,3 Until recently theassessment of tactile, proprioceptive, and visual functionshas formed an important component in the diagnosticformulation of developmental coordination disorder(DCD). This included the assumption that impaired sen-sorimotor integration underpinned the perceptual-motorproblems of these children and thus should be the focusof treatment (European Academy for Childhood Disabil-ity recommendations). The evidence for the benefits ofsensory motor treatments for children with DCD how-ever, is marginal.4 The sensory deficits of children withCP have been shown to affect movement production,particularly upper limb performance.3 Furthermore, chil-dren with CP with better sensory status have shown pro-longed retention of motor skill progress followingpractice.5

In both DCD and CP, the predominant disturbance tofunction is linked to atypical structural or functional con-nectivity within the central nervous system (CNS) affectingboth sensory and motor systems, although the neural basisof DCD has yet to be defined. Less well known though ishow the sensory system is affected in children with muscleweakness that is not due to atypical brain function or

development, such as in Duchenne muscular dystrophy(DMD), and what impact this may have on functionalmotor skills.

The study by Troise et al.6 draws attention to potentialsensory impairments associated with DMD. Their findingshighlight a dependence on visual feedback for manual dex-terity in the absence of impairments in either two-pointtactile discrimination or stereognosis. Their results, reflect-ing a greater discrepancy in the manual skills of youngmales with DMD than control children only when per-forming the manual task with the eyes closed, lead to anumber of hypotheses. While muscle weakness may haveplayed a role in the slower speeds for identifying objects,this does not provide an explanation for equivalent speedsin the manual dexterity task when the eyes were open. Theauthors have therefore conjectured that this may be due toreduced glucose metabolism although it is not particularlyevident that this may be due to lateralisation of hypo-metabolism to the right hemisphere.

Alternatively, Troise et al. also postulate that the depen-dence on visual feedback is similar to that in youngerchildren and therefore may reflect more generalized delaysin motor development in children with DMD. They didnot however explore proprioception directly.

It has been shown from both human and animal studiesthat the discharge from muscle spindles, which providethe main source of proprioceptive feedback to the CNS,is modulated by the contractile state of the skeletal mus-cles in which they are embedded.7 While Ribot-Ciscaret al.8 suggest that muscle spindle proprioceptive func-tions may in fact be spared in muscular dystrophy, theirsample only included four participants with DMD orBecker muscular dystrophy, the remaining with myotonic,fascioscapulohumeral, or limb-girdle dystrophies. The

Commentaries 805

sparing of intrafusal muscle fibres and proprioceptivefunctions may be limited to the more slowly progressivemuscular dystrophies.9

Troise et al. have provided an important basis for con-sideration of proprioceptive feedback in the assessment and

potential treatment of manual dexterity in DMD. Furtherexploration of the underpinnings of both sensory and per-ceptual control of movement across muscular dystrophiesis warranted, especially considering the implications fortreatment planning.

REFERENCES

1. Mon-Williams MA, Wann JP, Pascal E. Visual-proprio-

ceptive mapping in children with developmental coordi-

nation disorder. Dev Med Child Neurol, 1999; 41: 247–

54.

2. Yekufiel M, Jariwala M, Stretch P. Sensory deficit in the

hands of children with cerebral palsy: a new look at

assessment and prevalence. Dev Med Child Neurol 1994;

36: 619–24.

3. Auld ML, Boyd RN, Moseley L, Ware RS. Impact of

tactile dysfunction on upper-limb motor performance in

children with unilateral cerebral palsy. Arch Phys Med

Rehabil, 2012; 93: 696–702.

4. Blank R, Smits-Engelsman B, Polatajko H, Wilson P.

European Academy for Childhood Disability (EACD):

recommendations on the definition, diagnosis and inter-

vention of developmental coordination disorder (long

version). Dev Med Child Neurol, 2012; 54: 54–93.

5. Robert MT, Guberek R, Sveistrup H, Levin MF. Motor

learning in children with hemiplegic cerebral palsy and

the role of sensation in short-term motor training of

goal-directed reaching. Dev Med Child Neurol, 2013; 55:

1121–8.

6. Troise D, Yoneyama S, Resende MB, Reed U, Xavier

G, Hasue R. The influence of visual and tactile

perception on hand control in children with Duchenne

muscular dystrophy. Dev Med Child Neurol, 2014; 56:

882–87.

7. Wise AK, Fallon JB. The effect of muscle contraction

on kinaesthesia. Adv Exp Med Biol 2002; 508: 87–94.

8. Ribot-Ciscar E, Tr�efouret S, Aimonetti JM, Attarian S,

Pouget J, Roll JP. Is muscle spindle proprioceptive

function spared in muscular dystrophies? A muscle

tendon vibration study. Muscle Nerve 2004; 29:

861–6.

9. Aimonetti JM, Ribot-Ciscar E, Rossi-Durand C, Attari-

an S, Pouget J, Roll JP. Functional sparing of intrafusal

muscle fibers in muscular dystrophies. Muscle Nerve

2005; 32: 88–94.

Ketogenic diet in children with intractable epilepsy: what aboutresting energy expenditure and growth?

SIMONA BERTOLI1 | ALBERTO BATTEZZATI1 |ANNA TAGLIABUE2

1 Department of Food Environmental and Nutritional Sciences (DeFENS),International Center for the Assessment of Nutritional Status (ICANS), Milano;2 Department of Public Health, Experimental and Forensic Medicine, HumanNutrition and Eating Disorder Research Center, University of Pavia, Pavia, Italy.

doi: 10.1111/dmcn.12474

This commentary is on the original article by Groleau et al. on pages898–904 of this issue.

The study by Groleau et al.1 looks at the effect of ketogen-ic diet treatment on resting energy expenditure (REE) andgrowth in children with intractable epilepsy with and with-out cerebral palsy (CP) over 15 months. It is an attempt tobetter understand the metabolic and nutritional long-termeffects of the ketogenic diet in children at different degreesof risk for growth and body composition abnormalities.

In the last decade, only one study has focused on theeffects of the ketogenic diet on REE2 in children with intrac-table epilepsy without CP for over 6 months of dietary treat-ment. The authors stated that ketogenic diet treatmentincreases fat oxidation without significant changes in REE.These findings are confirmed in the present studysuggesting that the ketogenic diet does not change dailybasal metabolic rate both in the short- or in long-term.

From the available research it is hard to draw firm con-clusions on the effect of the ketogenic diet on growth.Quite often results are confounded by ketogenic dietarymanagement, follow-up protocol, duration of treatmentexposure, and pre-existing malnutrition (as in our own pre-vious investigation3). In this regard, the present study pro-vides an advance in this area. In line with previous research,results show that height z-score decreased overall frombaseline to 3 and 15 months, indicating height velocitydeceleration, particularly in children with CP. This couldsuggest differential mechanisms underlying the associationbetween the ketogenic diet and growth, possibly linked withthe putative effects of ketone bodies plasma level andchronic ketosis on intermediate metabolism and hormonesecretion (i.e. growth hormone and insulin-like growthfactor I) according to different neurological diseases.

Moreover, the ketogenic diet could act differently onnutritional status across the different developmental ages.In adults affected by glucose transporter 1 deficiency syn-drome (Glut1-DS) it was recently shown that the keto-genic diet over 5 years did not have any major negativeimpact on nutritional status.4 From this point of view,growth retardation could reflect the potential compensa-tory mechanisms of the neuro-endocrine axis to cope withthe ketogenic diet-induced alteration in protein metabo-lism.

806 Developmental Medicine & Child Neurology 2014, 56: 801–807