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Tract of goll and burdach

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Tracts of Goll and Burdach (Posterior Columns / Dorsal Columns)

The Tract of Goll (fasciculus gracilis) and the Tract of Burdach (fasciculus cuneatus) are the two subdivisions of the posterior (dorsal) columns of the spinal cord. Together they form the first leg of the Posterior Column-Medial Lemniscal (PCML) pathway, the main route for conscious proprioception, vibration sense, discriminative touch, and 2-point discrimination.

Names and Eponyms

EponymAnatomical NameMeaning
Tract of GollFasciculus gracilis"gracilis" = thin/slender
Tract of BurdachFasciculus cuneatus"cuneatus" = wedge-shaped

Location in the Spinal Cord

Both tracts sit in the dorsal funiculus (posterior white matter) of the spinal cord:
  • Fasciculus gracilis (Goll) - medial position
  • Fasciculus cuneatus (Burdach) - lateral position (lateral to gracilis)
Somatotopic organization of posterior columns - spinal cord cross-section showing gracile and cuneate fasciculi with their body representations

Somatotopic Organization

This is a high-yield point: fibers are arranged medial to lateral corresponding to sacral to cervical levels. As fibers ascend, incoming fibers from higher levels push existing fibers medially.
FasciculusSpinal levelsBody region
Gracilis (Goll) - medialSacral, lumbar, lower 6 thoracic (below T6)Legs and lower trunk
Cuneatus (Burdach) - lateralUpper 6 thoracic and all cervical (above T6)Upper trunk, arms, neck
Key point: The fasciculus cuneatus is only present above T6 because below that level, there is no upper limb input. So at lumbar and sacral levels, only the gracilis exists; the cuneate fasciculus appears from mid-thoracic levels upward.

Neurons and Course (3-Neuron Pathway)

1st Order Neuron (Peripheral to Spinal Cord)

  • Cell body in the dorsal root ganglion (DRG)
  • Large-diameter, heavily myelinated A-alpha and A-beta fibers
  • Enter the spinal cord via the medial dorsal root entry zone
  • Axons ascend ipsilaterally in the posterior column (do NOT synapse in the cord)
  • Some collaterals enter the dorsal horn gray matter to synapse on interneurons/motor neurons (contributes to spinal reflexes)

2nd Order Neuron (Spinal Cord to Thalamus)

  • 1st order fibers synapse at the posterior column nuclei in the medulla:
    • Gracilis → Nucleus gracilis
    • Cuneatus → Nucleus cuneatus
  • 2nd order axons then cross as internal arcuate fibers (decussation in the lower medulla)
  • Form the medial lemniscus on the contralateral side
  • The medial lemniscus initially has a vertical orientation in the medulla (feet ventral, "little person stands up"), then becomes horizontal in the pons and midbrain (legs lateral, arms medial - "little person lies down")
  • Terminate in the ventral posterior lateral (VPL) nucleus of the thalamus

3rd Order Neuron (Thalamus to Cortex)

  • VPL neurons project via the posterior limb of the internal capsule
  • Reach the primary somatosensory cortex (S1) in the postcentral gyrus (Brodmann areas 3, 1, and 2)
Posterior column-medial lemniscal pathway diagram showing spinal cord, medulla, brainstem, thalamus (VPL), and somatosensory cortex with peripheral receptors

Sensory Modalities Carried

ModalityReceptor
Proprioception (conscious)Muscle spindle primary afferents (Ia), Golgi tendon organ
Vibration sensePacinian corpuscles, Meissner's corpuscles, Merkel discs
Discriminative / fine touchMeissner's corpuscles, Merkel discs, Ruffini endings
2-point discriminationMultiple mechanoreceptors
Stereognosis, graphesthesia(cortical integration of above)

Key Features to Remember

FeatureDetail
Decussation levelLower medulla (as internal arcuate fibers)
Ipsilateral ascentYes - fibers stay ipsilateral until medulla
Fiber typeLarge myelinated (A-alpha, A-beta)
First synapseNucleus gracilis / nucleus cuneatus in medulla
Second synapseVPL nucleus of thalamus
Final destinationPostcentral gyrus (S1), areas 3, 1, 2
Cuneate fasciculus present fromT6 and above only

Clinical Relevance - Posterior Column Syndrome

Damage to the posterior columns causes ipsilateral loss of:
  • Proprioception (positive Romberg's sign)
  • Vibration sense
  • Fine touch and 2-point discrimination
  • Sensory ataxia
Pain and temperature are SPARED (those travel in the anterolateral spinothalamic tract).
Classic causes of posterior column damage:
  • Tabes dorsalis (neurosyphilis)
  • Subacute combined degeneration (Vitamin B12 deficiency)
  • Friedreich's ataxia
  • Multiple sclerosis
  • Cervical spondylosis
  • Posterior spinal artery infarct
Sources: Neuroanatomy through Clinical Cases, 3rd Ed. | Localization in Clinical Neurology, 8th Ed.
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